Augmentation of atrial contribution to left ventricular inflow with aging as assessed by intracardiac Doppler flowmetry

Normal values and reproducibility of left ventricular filling parameters by radionuclide angiography

BACKGROUND

In physiologic situations age, heart rate (HR) and left ventricular ejection fraction (EF) may influence left ventricular filling rate. In this study, we determined normal values for radionuclide angiography (RNA) derived diastolic filling parameters, the correlations with age, HR and EF and their reproducibility.

METHODS

The study was performed in 20 patients, 40-76 years old (mean 57), with normal findings at coronary angiography and left ventriculography. The first RNA was performed at rest (RNA1). Then, five minutes bicycle ergometry was performed and the patients were allowed five minutes rest before RNA was repeated (RNA2). From the left ventricular time activity curve we determined peak filling rate (PFR), time to peak filling rate (TPFR) and atrial contribution (AC) to ventricular filling.

RESULTS

Values for PFR1 were 2.2 +/- 0.6 EDV/sec (PFR2 2.4 +/- 0.7 EDV/sec, r = 0.82), for TPFR1 198 +/- 22 msec (TPFR2 203 +/- 24 msec, r = 0.45) and for AC1 31 +/- 11% (AC2 31 +/- 10%, r = 0.72). The correlations of PFR and TPFR with age were statistically significant (respectively r = -0.68 and r = 0.48, P < 0.05). PFR was also influenced by HR and EF (resp. r = 0.51 and r = 0.50, P < 0.05). TPFR however was not influenced by HR and EF, whereas AC was positively correlated with HR (r = 0.79, P < 0.01).

CONCLUSIONS

Radionuclide angiography is a reliable and reproducible method to assess parameters of diastolic left ventricular filling in individual patients. It may therefore be used to serially follow diastolic function. When used for interindividual comparison the dependency of RNA derived left ventricular filling parameters on age, HR and EF should however be considered.

Clinical application of pulsed Doppler tissue imaging for assessing abnormal left ventricular relaxation

Conventional assessment of left ventricular (LV) relaxation by calculating the time constant of LV pressure decay during the isovolumic diastole requires an invasive approach. Conversely, noninvasive parameters obtained by measuring isovolumic relaxation time and transmitral flow velocity often give inaccurate information. Using LV pressure curve, pulsed Doppler echocardiography, and pulsed Doppler tissue imaging in 38 patients with heart disease and 12 control subjects, we calculated the time constant and recorded transmitral flow velocity and motion velocities at the endocardial portions of the ventricular septum and LV posterior wall. Compared with the controls, patients exhibited a prolonged time constant, a decreased peak early diastolic velocity of the LV posterior wall, and a prolonged time interval from the second heart sound to the peak of the early diastolic wave. The time constant correlated well with the isovolumic relaxation time and various parameters calculated from the transmitral flow velocity, except in patients with elevated LV end-diastolic pressure. In all subjects, the time constant correlated negatively with the peak early diastolic velocity of the posterior wall and positively with the time from the second heart sound to the peak of the early diastolic wave. Thus, early diastolic parameters derived from the motion velocity of the LV posterior wall by pulsed Doppler tissue imaging were closely related to the time constant. This technique may allow noninvasive evaluation of abnormal LV relaxation in patients with various heart diseases.

The noninvasive assessment of left ventricular diastolic function with two-dimensional and Doppler echocardiography

Left ventricular diastolic filling can be determined reliably by Doppler-derived mitral and pulmonary venous flow velocities. Diastolic filling abnormalities are broadly classified at their extremes to impaired relaxation and restrictive physiology with many patterns in between. An impaired relaxation pattern identifies patients with early stages of heart disease, and appropriate therapy may avert progression and functional disability. Pseudonormalization is a transitional phase between abnormal relaxation and restrictive physiology and signifies increased filling pressure and decreased compliance. In this phase, reducing preload, optimizing afterload, and treating the underlying disease are clinically helpful. A restrictive physiology pattern identifies advanced, usually symptomatic disease with a poor prognosis. Therapeutic intervention is directed toward normalizing loading conditions and improving the restrictive filling pattern, although this may not be feasible in certain heart diseases. Finally, many patients have left ventricular filling patterns that appear indeterminate or mixed. In these cases, clinical information, left atrial and left ventricular size, pulmonary venous flow velocity, and alteration of preload help assess diastolic function and estimate diastolic filling pressures.

Noninvasive Doppler-derived myocardial performance index: correlation with simultaneous measurements of cardiac catheterization measurements

A simple, reproducible, noninvasive Doppler index for the assessment of overall cardiac function has been described previously. The purpose of this study was to correlate the Doppler index with accepted indexes of cardiac catheterization of left ventricular performance. Thirty-four patients with ischemic heart disease or idiopathic dilated cardiomyopathy prospectively underwent a simultaneous cardiac catheterization and Doppler echocardiographic study. Invasive measurements of peak +dP/dt, peak -dP/dt, and tau were obtained from the high-fidelity left ventricular pressures. A Doppler index of myocardial performance was defined as the summation of isovolumetric contraction and relaxation time divided by ejection time. There was a correlation between Doppler measurement of isovolumetric contraction time and peak +dP/dt (r = 0.842; p < 0.0001) and Doppler measurement of isovolumetric relaxation time and peak -dP/dt (r = 0.638; p < 0.001). Left ventricular ejection time correlated with both peak +dP/dt (r = 0.539; p < 0.001) and peak -dP/dt (r = 0.582; p < 0.001). The Doppler index correlated with simultaneously recorded systolic peak +dP/dt (r = 0.821; p < 0.0001) and diastolic peak -dP/dt (r = 0.833; p < 0.001) and tau (r = 0.680; p < 0.0001). This study documents that a simple, easily recordable, noninvasive Doppler index of myocardial performance correlates with invasive measurement of left ventricular systolic and diastolic function and appears to be a promising noninvasive measurement of overall cardiac function.

Effects of aging on left ventricular relaxation in humans. Analysis of left ventricular isovolumic pressure decay

BACKGROUND

Some experimental studies in animals have shown that myocardial relaxation is prolonged with aging. However, it is not known whether aging alters ventricular isovolumic relaxation in human subjects.

METHODS AND RESULTS

We analyzed high-fidelity left ventricular pressures, measured by use of a catheter-tipped manometer, and biplane left ventriculograms in 55 normal subjects who underwent diagnostic cardiac catheterization but who were found to have normal cardiac anatomy and function. There were 38 men and 17 women, ranging in age from 20 to 77 years. Left ventricular isovolumic relaxation was assessed by the exponential time constants of isovolumic pressure decay with (Tb) and without (Tw) an asymptote pressure. Left ventricular volume, ejection fraction, and wall thickness or mass were calculated from left ventricular angiograms. Neither of the time constants of left ventricular relaxation correlated with age (Tb: r = .001 to .10, P = NS: Tw: r = .02 to .05, P = NS). Left ventricular systolic function (ie, ejection fraction and end-systolic volume index), heart rate, and left ventricular wall thickness or mass, which are major hemodynamic determinants of left ventricular relaxation, were not significantly affected by aging. The multivariate analysis of age and hemodynamic variables against the time constants of left ventricular relaxation also indicated that no significant relation was found between age and left ventricular relaxation.

CONCLUSIONS

In the absence of coronary artery disease, systemic hypertension, left ventricular systolic dysfunction, or hypertrophy, left ventricular relaxation assessed by the time constant of isovolumic pressure decay remains essentially unchanged with normal adult aging, at least until the eighth decade.

An index of early left ventricular filling that combined with pulsed Doppler peak E velocity may estimate capillary wedge pressure

OBJECTIVES

This study sought to determine the applicability of the combined information obtained from transmitral Doppler flow and color M-mode Doppler flow propagation velocities for estimating pulmonary capillary wedge pressure.

BACKGROUND

Although Doppler-derived measurements of left ventricular (LV) filling have been applied to determine left atrial pressure, their accuracy has been limited by the variable effect of ventricular relaxation in these indexes. Recently, flow propagation velocity measured by color M-mode Doppler echocardiography has been suggested as an index of ventricular relaxation.

METHODS

We studied 45 patients admitted to the intensive care unit who underwent invasive hemodynamic monitoring. We measured peak early (E) and late (A) transmitral Doppler velocities, E/A ratio and flow propagation velocity (vp) and compared them by linear regression with pulmonary capillary wedge pressure (pw).

RESULTS

We found a modest positive correlation between pw and E (r = 0.62, p < 0.001) and the E/A ratio (r = 0.52, p < 0.001) and a negative correlation between pw and vp (r = -0.34, p = 0.02). By stepwise linear regression, only E and vp were statistically significant predictors of pw. However, the E/vp ratio provided the best estimate of pw (r = 0.80, p < 0.001; pw = 5.27 x [E/vp] + 4.6, SEE 3.1 mm Hg).

CONCLUSIONS

The ratio of component velocity (E) over the color M-mode propagation velocity during early LV filling, by correcting for the effect of LV relaxation, provides a better estimate of pw than standard measurements of transmitral Doppler flow.

The importance of different atrioventricular delay for left ventricular filling in sequential pacing: clinical implications

We assessed the influence and clinical consequences of different AV delay on ventricular filling in 30 patients (mean age 60 +/- 5 years) who had DDD pacemakers for AV block. All 30 patients presented a normal ejection fraction, but in 18 cases (Group I), an echo-Doppler examination revealed ventricular hypertrophy (mean end-diastolic wall thickness of 1.4 +/- 0.16 cm, LV mass index 155 +/- 17 g/m2), and an abnormal relaxation pattern (isovolumetric relaxation time = 124.72 +/- 11.82; early to late peak velocity = 0.6 +/- 0.03; deceleration time = 296.83 +/- 34.02 ms). Group II included the remaining 12 patients who had a normal filling pattern. In all 30 patients, the pattern was reassessed following modification of the AV delay (200, 150, 100, and 75 ms). Patients at baseline (AV delay of 200 ms) also underwent an exercise test with determination of respiratory gas exchange. In Group I, 13 (72.5%) patients were classified as Weber class B (VO2 Max 16.8 +/- 1.7 mL/min per kg); and 5 (27.5%) were Class A (VO2 Max 22.5 +/- 1.4 mL/min per kg). In Group II, all 12 patients were classified as Weber Class A. In Group II, changes in AV delay caused no consistent variations in filling pattern, and therefore AV delay was not modified. In Group I patients, since reduction to 100 ms resulted in normalization of the filling pattern, the AV delay was programmed to 100 ms. A graded exercise test repeated after 6 months' follow-up showed an improved Weber class in 13 patients (from B to A) and greater VO2 Max in the remaining five already in Class A. We concluded that, in sequential paced patients with normal ejection fraction but abnormal relaxation pattern, modification in AV delay can induce normalization of filling and improvement in cardiac functional capacity.

Clinical relevance of about-yearly changes in blood pressure and the environment

Changes identified by inferential statistics from summer to winter of high to low arterial blood pressures (BP) have been quantified as a large predictable about-yearly BP swing. This condition of a large annual BP amplitude (LABPA) raises concern about hypotension as well as hypertension and raises new questions regarding appropriate guidelines for diagnosis and treatment. Recommendations made in the fall on the basis of data collected in the summer may be totally inadequate in dealing with the patient's condition in the winter. In order to avoid such mistakes, it is imperative to implement a systematic surveillance of BP in the light of current chronobiological limits. Patients with a large circannual BP amplitude are particularly suited for a study of the underlying hormonal mechanisms. The longitudinal monitoring of their BP is also amenable to the study of environmental influences from near and far.

Cardiovascular adaptation to orthostatic stress during vasodilator therapy

BACKGROUND

Orthostatic hypotension is a dangerous problem in elderly patients, often exacerbated by vasodilator medications. Age- and disease-related impairments in cardioacceleration and diastolic ventricular function may make older patients particularly vulnerable to the hypotensive effects of these drugs. Therefore we aimed to determine mechanisms of postural blood pressure regulation in elderly patients with coronary artery disease and to compare the effects of isosorbide dinitrate and nicardipine hydrochloride on postural blood pressure homeostasis in these patients.

METHODS

Twenty elderly subjects with stable coronary artery disease (age, 76 +/- 4 [SD] years) underwent a baseline evaluation followed by a double-blind, randomized crossover comparison of nicardipine (20 mg by mouth t.i.d.) versus isosorbide (20 mg by mouth t.i.d.). Doppler echocardiography and a 15-minute 60-degree head-up tilt test were conducted on no study medications and then after successive 3-week treatment periods with nicardipine or isosorbide. Blood pressure, heart rate, vascular resistance, cardiac output, and spectral characteristics of heart rate and blood pressure variability were measured before and during each tilt.

RESULTS

Isosorbide treatment was associated with a higher prevalence of symptoms of cerebral hypoperfusion and a failure to increase systemic vascular resistance during tilt. While taking isosorbide subjects were able to preserve cardiac output and maintain upright blood pressure through enhanced cardioacceleration. During nicardipine treatment systemic vascular resistance and low-frequency blood pressure variability were reduced, but the ability to increase systemic vascular resistance during tilt was preserved.

CONCLUSIONS

Although nicardipine may decrease vascular responsiveness to sympathetic activation, the baroreflex-mediated vasoconstrictor response to upright tilt remains intact. In contrast, isosorbide impairs the systemic vascular response to orthostatic stress in elderly patients with stable coronary artery disease.

Risks and benefits of combined maze procedure for atrial fibrillation associated with organic heart disease

OBJECTIVES

This study sought to identify the risks and benefits of adding the maze procedure in patients with atrial fibrillation (AF) undergoing operation for underlying organic cardiac disorders.

BACKGROUND

Persistent AF often leaves patients symptomatic even after otherwise successful cardiac surgery.

METHODS

Fifty-one patients undergoing valvular operation and the maze procedure (n = 43) or repair of congenital anomalies (n = 8) combined with the maze procedure were compared with 51 patients (control group) matched for underlying diseases and procedures except for the maze operation. Each group, including 31 patients with a concomitant tricuspid annuloplasty and 12 undergoing reoperation, were similar in age, duration of arrhythmia, degree of cardiomegaly and New York Heart Association functional class.

RESULTS

Patients undergoing the maze procedure had longer cardiopulmonary bypass time (213 vs. 144 min, p < 0.0001), longer cardiac arrest (134 vs. 93 min, p < 0.0001) and greater blood loss with longer respiratory care (39 vs. 18 h p = 0.021) and intensive care unit stay but no mortality. No significant differences were found in catecholamine or transfusion requirements immediately after operation. Sustained AF was much less frequent in the maze group (12% at 1 year) than the control group (86%, p < 0.0001), with an average follow-up period of 32 months (range 25 to 42). Atrial contraction was documented in 41 (80%) and 40 (78%) patients for right and left ventricular filling, respectively, after the maze procedure, resulting in a significantly smaller cardiac size and improved functional capacity. Medication was discontinued in seven patients in the maze group compared with two in the control group.

CONCLUSIONS

Improved restoration of atrial rhythm and contraction with combined maze operation appeared to justify the increased operative time and complexity and postoperative care.

Analysis of left ventricular diastolic function

Our understanding of left ventricular diastolic function has evolved with our understanding of Doppler echocardiographic assessment of left ventricular filling dynamics. Left ventricular diastolic function consists of several variables which affect the Doppler echocardiographic recordings in a complex way. While there are still limitations with the non-invasive assessment of left ventricular diastolic function and filling pressures by Doppler echocardiography, great progress has been made and careful interpretation of properly obtained Doppler recordings can give clinically relevant information concerning left ventricular diastolic function, filling pressures, and prognosis in patients with cardiac disease.

A peculiar form of pacemaker syndrome in DDD pacing

This paper documents the occurrence of a peculiar form of PM syndrome despite the presence of DDD pacing. This occurred because the post atrial refractory period was set inappropriately. Our aim is to highlight the intriguing nature of the syndrome and the need to rule out a concealed form of PM syndrome every time an implanted patient suffers from unexplained and confounding symptoms.

Left ventricular diastolic function in young adults: the Coronary Artery Risk Development in Young Adults Study

Doppler transmitral flow velocities have been used to assess left ventricular diastolic function. Associations of transmitral velocities with specific physiologic variables and cardiovascular risk factors have not been reported previously in a large population-based study of young adults. We performed Doppler analysis of left ventricular inflow in 3492 black and white men and women (aged 23 to 35 years) in the year-5 examination of the Coronary Artery Risk Development in Young Adults (CARDIA) Study. First third filling fraction, peak flow velocity in early diastole (PFVE), peak flow velocity in late diastole (PFVA), and the PFVA/PFVE ratio were measured. Women had higher PFVE and PFVA than had men (PFVE: 0.81 +/- 0.13 m/sec versus 0.76 +/- 0.13 m/sec; PFVA: 0.47 +/- 0.11 m/sec versus 0.43 +/- 0.10 m/sec; both p < 0.001). Gender-specific multiple regression analyses showed that age, heart rate, systolic blood pressure, left ventricular percent fractional shortening, and body weight were independently and positively related to PFVA (all p < 0.001) in men and women. Age, heart rate, and forced expiratory lung capacity in 1 second were inversely related to PFVE and first third filling fraction (both p < 0.01). Left ventricular percent fractional shortening was positively related to PFVE and first third filling fraction (p < 0.001). Age, heart rate, and body weight were positively correlated with the PFVA/PFVE ratio (all p < 0.001). Height had weak negative associations with PFVA and PFVE in women only. These results suggest that, in young adults, Doppler measures of left ventricular diastolic filling are related to age, sex, body weight, blood pressure, heart rate, left ventricular systolic function, and lung function.

Modified maze procedure for patients with atrial fibrillation undergoing simultaneous open heart surgery

BACKGROUND

Persistent atrial fibrillation (AF) leaves patients symptomatic and at increased risk of thromboembolism even after otherwise successful cardiac surgery.

METHODS AND RESULTS

To treat AF secondary to cardiac lesions requiring surgery, we combined a modified maze procedure in 101 patients simultaneously undergoing valvular procedures (87), repair of congenital anomalies (12), and other procedures (2), including 24 repeat operations. Duration of AF varied from 0.1 to 30 years (average +/- SD, 8.8 +/- 7.0 years); the f-wave voltage ranged from 0 to 0.45 mV (0.15 +/- 0.09 mV); and cardiothoracic ratio varied from 40% to 99% (63 +/- 9%). Aortic cross-clamp time varied from 75 to 229 minutes (138 +/- 31 minutes), with bypass time ranging from 119 to 326 minutes (217 +/- 42 minutes). There were two early deaths (2%), no late deaths, and one episode of transient neurological ischemic attack in follow-up ranging from 1.0 to 3.1 years, for a total of 190 patient-years. Postoperative rhythms were sinus in 83 patients (82%), junctional in 4 (4%), and persistent AF in 14 (14%), each of whom had mitral valve disease. Patients with other underlying pathology had complete recovery of atrial rhythm. A normal-sized A wave was detected in 88% for transtricuspid flow and in 73% for transmitral flow, suggesting concomitant recovery of atrial contraction. Among 36 patients without mechanical valves, 30 (83%) with atrial rhythm and contraction have been taken off anticoagulation therapy, including 10 who are free of all medication.

CONCLUSIONS

The results suggest that the combined approach is safe, effective, and indicated in patients who are judged capable of tolerating the procedure and likely to regain atrial rhythm.

Is the pulmonary venous-transmitral A-wave duration difference altered by age and hypertension?

We have demonstrated that the pulmonary venous and transmitral atrial duration, and the difference between the 2 are independent of age and not influenced by hypertension, but have a high interobserver variability and range of variability. Enthusiasm for this parameter with the currently available recording techniques must be tempered by the high variability in this measurement.

Pulmonary vein Doppler flow patterns specific for elevated left ventricular filling pressures in older cardiac patients are common in healthy adults < 40 years old

In older cardiac patients, elevated left-sided heart filling pressures are predicted by both a systolic PV flow fraction < 40% and a greater duration during atrial systole of reversal flow into the PVs than forward flow through the mitral valve. However, this study shows that these Doppler findings are not uncommon in younger subjects without cardiac disease. Use of these PV Doppler flow parameters to assess LV filling pressures should be limited to older patients.

Left atrial function after Cox's maze operation concomitant with mitral valve operation

BACKGROUND

This study examined whether the atrial fibrillation that commonly occurs in patients with a mitral valve operation could be eliminated by a concomitant maze operation.

METHODS

Left atrial function after Cox's maze operation performed concomitantly with a mitral valve operation was evaluated in 10 patients ranging in age from 38 to 67 years (mean age, 54 years). Seven patients who had had coronary artery bypass grafting served as the control group. Using transthoracic echocardiography, the ratio between the peak speed of the early filling wave and that of the atrial contraction wave (A/E ratio) and the atrial filling fraction (AFF) were determined from transmitral flow measurements. These two indices have been considered to represent the contribution of left atrial active contraction to ventricular filling.

RESULTS

The A/E ratio and the AFF were significantly lower in the maze group (0.35 +/- 0.17 versus 0.97 +/- 0.28 [p < 0.01] and 17.6% +/- 8.8% versus 36.8% +/- 6.4% [p < 0.01], respectively). The A/E ratio and the AFF correlated inversely with age (r = -0.72, p < 0.05 and r = 0.76, p < 0.05, respectively) in the maze group. In an angiographic study, the mean left atrial maximal volume index in the maze group was approximately three times larger than that in the control group (117.5 +/- 24.3 mL/m2 versus 35.3 +/- 6.6 mL/m2 [p < 0.01]). The left atrial active emptying volume index was significantly smaller in patients in the maze group (7.2 +/- 2.5 mL/m2 versus 13.1 +/- 4.6 mL/m2 [p < 0.01]).

CONCLUSIONS

After the maze procedure performed concomitantly with a mitral valve operation in patients with a dilated left atrium, left atrial contraction is detectable but incomplete in the elderly.

Physical work capacity with rate responsive ventricular pacing (VVIR) versus dual chamber pacing (DDD) in patients with normal and diminished left ventricular function

To determine the benefit of atrial contribution on work capacity in relation to left ventricular ejection fraction, we studied 17 patients (68 +/- 13 years) with dual chamber pacemakers (DDD) implanted for high degree atrioventricular (AV) block. In random order they were assigned to rate responsive ventricular (VVIR) and to atrial triggered ventricular (VDD) stimulation. Maximum oxygen uptake (max VO2), that correlates best with work capacity, was measured by spiroergometry at a respiratory quotient of 1.1 during treadmill exercise test. Left ventricular ejection fraction at rest was determined by radionuclide ventriculography during VDD-stimulation and an AV delay of 150 ms. There were no differences between these two pacing modes relating heart rate, blood pressure, minute ventilation, exercise duration and maximal work load. In eight patients with an ejection fraction > 50% (60 +/- 10%), but not in nine patients with an ejection fraction < 50% (41 +/- 10%), maximum oxygen uptake was significantly higher (P < 0.01) during atrial triggered ventricular pacing (1440 +/- 533 ml/min) compared with rate responsive ventricular pacing (1328 +/- 536 ml/min). Thus, rate responsive single chamber pacemakers largely enable the same work capacity as dual chamber pacemakers in patients with high degree AV block. Patients with normal left ventricular function may profit most from preserved AV synchrony as shown by the higher maximum oxygen uptake on exercise.

Relationship between left ventricular wall thickness and left atrial size: comparison with other measures of diastolic function

We postulated that in patients with essential hypertension and normal left ventricular (LV) systolic function, left atrial (LA) size correlates with LV wall thickness by better reflecting the chronicity and duration of LA hypertension than the commonly used hemodynamic and Doppler measures of LV diastolic function. Accordingly, hemodynamic, Doppler, and two-dimensional echocardiographic measurements were performed in 30 subjects with no cardiovascular abnormalities other than essential hypertension (mean systolic blood pressure of 150 +/- 29 mm Hg). The mean LV wall thickness was 0.57 +/- 0.14 cm/m2 and the mean LV ejection fraction was 0.62 +/- 0.12. Hemodynamic and Doppler measures including pulmonary capillary wedge and LV end-diastolic pressures, isovolumic LV pressure relaxation, LV chamber elastic stiffness, and E/A ratio (E and A waves on the pulsed Doppler signal of the mitral valve) correlated poorly (r = 0.01 to -0.52) with LV wall thickness. Both E/A ratio and isovolumic LV pressure relaxation correlated better (p = 0.05) with patient age than with LV wall thickness. In contrast, LA area (in the apical four-chamber view) had a good correlation (r = 0.77 for LA area in atrial diastole and r = 0.86 for LA area in atrial systole) with LV wall thickness. Multiple regression analysis revealed LA area in atrial systole to be the best correlate of LV wall thickness. We conclude that because the left atrium is a thin-walled structure, its size may increase with an increase in LA pressure. In the absence of mitral valve disease and atrial fibrillation, LA size may reflect the chronicity and duration and thus the history of LA hypertension. LA size in the apical four-chamber view may, therefore, provide a simple noninvasive assessment of the degree of LV diastolic dysfunction.

Transthoracic Doppler assessment of pattern of left ventricular dysfunction in hypertensive heart disease: combined analysis of mitral and pulmonary venous flow velocity patterns

Although mitral flow velocity pattern changes with the progression of left ventricular (LV) diastolic dysfunction, it lacks predictive value in individual patients because of pseudonormalization in the presence of congestive heart failure and many physiologic and pathologic contributors to the mitral flow velocity pattern. To determine whether analysis of pulmonary venous flow velocity patterns complements the information obtainable from the mitral flow velocity patterns in the evaluation of patterns of LV dysfunction of hypertensive heart disease in individual patients, the ratio of the peak early diastolic filling velocity/peak filling velocity at atrial contraction (E/A ratio) in the mitral flow velocity pattern and the ratio of the peak systolic forward flow velocity (S)/peak diastolic forward flow velocity (D) (S/D ratio) in the pulmonary venous flow velocity pattern by the transthoracic approach were determined in 107 hypertensive patients with and without congestive heart failure. Age-related normal values of the E/A and S/D ratios were determined in 61 normal subjects and used to judge the normality or abnormality of the patterns. Results of the study indicate that (1) although an increased mitral E/A ratio is strongly indicative of heart failure with normal LV systolic function, the mitral E/A ratio is frequently within the normal range in hypertensive patients with heart failure; (2) association of decreased pulmonary venous S/D ratios with a normal mitral flow velocity pattern indicates the presence of heart failure as a result of LV systolic dysfunction that is usually observed at the most advanced pattern of LV dysfunction; (3) mild LV diastolic dysfunction is likely to exist in patients with normal E/A ratios if the pulmonary venous S/D ratio is higher than normal value; (4) predictive accuracy in the detection of LV systolic and diastolic dysfunction would be improved if both mitral and pulmonary venous flow velocity patterns rather than the mitral flow velocity pattern alone were analyzed. In conclusion, analysis of pulmonary venous flow velocity recordings improves accuracy and reliability of the Doppler assessment of LV systolic and diastolic dysfunction, particularly in individual hypertensive patients with normal mitral flow velocity patterns.

Improvement of the age-related impairment in left ventricular diastolic filling with verapamil in the normal human heart

BACKGROUND

Left ventricular (LV) diastolic function declines with the normal aging process. Because these changes are related to impaired active LV relaxation as well as to structural alterations, we hypothesized that verapamil might improve LV filling in elderly normal subjects compared with young normal subjects.

METHODS AND RESULTS

We studied 27 normal volunteers (between 20 and 71 years old), with normal exercise tests and echocardiograms, by radionuclide angiography before and after 3 to 4 days of oral verapamil therapy. Indexes of global LV function were derived from analysis of background-corrected time-activity curves. Subjects were recruited from three age groups: young (26 +/- 4 years, n = 10), middle-aged (46 +/- 5 years, n = 9), and elderly (66 +/- 3 years, n = 8). Baseline resting heart rate, blood pressure, peak systolic wall stress, and LV ejection fraction did not differ among groups. Baseline peak LV filling rate (expressed in fractional stroke volume per second) was reduced in the middle-aged group (5.8 +/- 1.2, P < .01) and the elderly group (4.3 +/- 1.0, P < .01) compared with the young group (7.8 +/- 1.2). With verapamil, resting heart rate, peak systolic wall stress, LV ejection fraction, and peak ejection rate did not change in any group. Peak filling rate increased in the middle-aged group (to 6.8 +/- 1.5 SV/s, P < .01) and the elderly group (to 5.7 +/- 1.0 SV/s, P < .01) but did not change in the young group (8.0 +/- 1.4 SV/s). Also, time to peak filling rate decreased with verapamil in the elderly group (from 185 +/- 31 to 147 +/- 15 milliseconds, P < .01). The magnitude of change in filling rate was correlated positively with age (r = .55, P < .005).

CONCLUSION

Verapamil selectively enhances LV diastolic filling in middle-aged and elderly subjects, compared with young adults, without affecting systolic function. This observation supports the hypothesis that the impairment of LV filling accompanying the normal aging process is, at least in part, a reversible phenomenon.

Radiofrequency catheter ablation in the treatment of supraventricular tachycardia in the elderly

OBJECTIVES

The purpose of this study was to evaluate the efficacy and safety of radiofrequency catheter ablation for the treatment of supraventricular tachycardias in an elderly (> or = 70 years of age) group of patients.

BACKGROUND

Supraventricular tachycardias are the most common form of cardiac arrhythmia and affect all age groups. Although usually well tolerated in youth, supraventricular tachycardias may be associated with disabling symptoms and have life-threatening potential in the elderly. In addition, antiarrhythmic agents are less well tolerated and may be associated with a higher incidence of toxicity in the elderly.

METHODS

From May 1989 to March 1993, 454 patients underwent a radiofrequency catheter ablation procedure at the University of California, San Francisco, for the treatment of symptomatic supraventricular tachycardia. Sixty-seven of these patients were > or = 70 years of age and constituted the study group. Patients underwent one of the following catheter ablation procedures: complete atrioventricular (AV) junctional ablation for ventricular rate control in patients with atrial fibrillation (37 patients), AV node modification for the treatment of AV node reentrant tachycardia (17 patients), accessory pathway ablation (9 patients), ablation of the "slow zone" to cure atrial flutter (4 patients) and atrial tachycardia ablation (1 patient). One patient underwent ablation for both AV node reentrant tachycardia and atrial flutter.

RESULTS

Success was achieved in 67 (98.5%) of 68 ablation procedures. There were no procedural or early deaths. The overall complication rate was 7.4%, and only one patient (1.5%) had long-term sequelae (permanent cardiac pacing for complete heart block). At a mean (+/- SD) follow-up of 22.1 +/- 12.9 months, 63 (94%) of 67 patients were alive, with no antiarrhythmic agents for the treatment of their presenting arrhythmia.

CONCLUSIONS

In this series radiofrequency catheter ablation appears to be an effective and safe treatment option for elderly patients (> or = 70 years of age) with a variety of symptomatic, drug-resistant supraventricular tachycardias. Because of the high incidence of severe symptoms associated with tachycardic episodes, the expense and the possible severe proarrhythmic problems associated with antiarrhythmic medications in this age group, catheter ablation may be considered an early rather than a "last resort" treatment option.

Morbidity of ischemic heart disease in early breast cancer 15-20 years after adjuvant radiotherapy

PURPOSE

To assess the cardiac side effects, primarily the occurrence of ischemic heart disease in symptom-free patients with early breast cancer treated with radiotherapy.

METHODS AND MATERIALS

Thirty-seven survivors of a former randomized study of early breast cancer were examined. Twenty patients irradiated pre- or postoperatively for left sided disease (study group patients) were compared with 17 controls who were either treated for right sided disease, or were nonirradiated patients. Radiotherapy was randomized in the original study; either tangential field 60Co, or electron-therapy was delivered. Echocardiography and bicycle ergometry stress test with 99mTc SestaMIBI myocardial perfusion scintigraphy were carried out and the patients' major risk factors for ischemic heart disease were also listed.

RESULTS

Our results showed a significant difference between the scintigraphic findings of the two groups. Five of the 20 study group patients (25%), while none of the 17 controls exhibited some kind of significant defects on scintigraphy, indicating ischemic heart disease (p < 0.05). No deterioration in left ventricular systolic and/or diastolic function could be detected by echocardiography.

CONCLUSION

Radiotherapy for left sided breast cancer with the mentioned treatment technique may present as an independent risk factor in the long-term development of ischemic heart disease, while left ventricular dysfunction could not be related to the previous irradiation. We emphasize the need to optimize adjuvant radiotherapy for early breast cancer by considering the dose both to the heart as well as the cancer.

Permanent cardiac pacemakers in the elderly

OBJECTIVE

To review (1) Changes in cardiac impulse generation, conduction, and ventricular filling in normal aging and disease; (2) Pacemaker technology and nomenclature; (3) Expert guidelines about pacemaker use; (4) Studies of pacemaker effectiveness and utilization.

DESIGN

Articles were identified through a Medline search, review of articles' bibliographies, and contact with pacemaker manufacturer representatives for information on device features and costs. These articles were reviewed, and the relevant data are presented.

RESULTS

Abnormalities in impulse generation and conduction are common in the elderly. Pacemaker use is higher in the elderly than in other population groups. Hemodynamic changes associated with aging include an increased contribution of atrial contraction to ventricular filling. Pacemakers, which maintain the synchrony between the atria and ventricles, may be particularly advantageous in the elderly for this reason. Rate-responsive ventricular pacemakers improve the quality of life compared with fixed rate devices in some patients over the age of 75. Dual-chamber, sequential pacemakers are more likely to reduce symptoms of pacemaker syndrome than ventricular pacemakers and probably also prolong survival and reduce risk of atrial fibrillation in certain groups of patients. However, dual chamber devices are more expensive and require more frequent follow-up. Pacemaker utilization can vary widely by region. Decisions about pacemakers require explicit tradeoffs between risk and quality of life on one hand and cost on the other. In many clinical situations, there is controversy as to whether pacemakers should be used.

CONCLUSIONS

Pacemakers provide definite benefits to some patients, whereas in others, the likelihood of benefit is uncertain. More sophisticated devices may provide some additional benefit, but they are more costly. Further data is still required to define precisely which groups of patients substantially benefit from complex and expensive pacing modalities compared with simpler ones.

Effects of age on left ventricular dimensions and filling dynamics in 117 normal persons

OBJECTIVE

To determine standard left ventricular Doppler measurements in a large reference group of various ages to reflect the senescence process.

DESIGN

We prospectively studied the influence of aging on left ventricular diastolic filling by performing Doppler echocardiography in 117 normal healthy volunteers.

MATERIAL AND METHODS

Transthoracic pulsed-wave Doppler echocardiographic studies of pulmonary venous flow and left ventricular inflow were done in the 53 male and 64 female study subjects. For analysis, the study subjects were arbitrarily classified into two groups: those younger than 50 years of age (group 1; N = 61) and those 50 years old or older (group 2; N = 56).

RESULTS

A striking difference was found in pulmonary venous flow and left ventricular inflow between group 1 and group 2 subjects. Group 2 had increased pulmonary venous peak systolic flow velocity (71 +/- 9 versus 48 +/- 9 cm/s), decreased peak diastolic flow velocity (38 +/- 9 versus 50 +/- 10 cm/s), increased peak atrial reversal flow velocity (23 +/- 4 versus 19 +/- 4 cm/s), and increased percentage of forward flow in systole (65 +/- 7 versus 55 +/- 8%) in comparison with group 1. In group 2, peak early filling velocity (62 +/- 14 versus 72 +/- 14 cm/s) and ratio of early filling to atrial filling (1.1 +/- 0.3 versus 1.9 +/- 0.6) were lower and peak atrial filling velocity (59 +/- 14 versus 40 +/- 10 cm/s) was higher than in group 1. Deceleration time (210 +/- 36 versus 179 +/- 20 ms) and isovolumic relaxation time (90 +/- 17 versus 76 +/- 11 ms) were prolonged in group 2 in comparison with group 1.

CONCLUSION

This study confirms the major influence of the aging process on left ventricular diastolic function in a large series of normal subjects. This physiologic factor should be considered in Doppler assessment of left ventricular diastolic filling in future studies.

Critical care for the elderly patient

Elderly individuals will continue to make up a major portion of patients requiring critical care. Age and chronic disease-related factors blunt the reserves with which the elderly can meet the demands of critical surgical illness. The clinician must remain vigilant to subtle changes in the patient's course which may indicate a developing complication and must pay attention to all the details of comprehensive critical care management. With careful attention and timely physiologic support, the elderly patient has as good a chance of surviving as a similarly ill younger patient, although his or her course may be more prolonged. The priorities are the same. Thus, the primary disease must be addressed: necrotic tissue débrided, pus drained, wounds closed, fractures set. Cardiopulmonary performance (oxygen delivery) must be maintained sufficiently to meet the heightened oxygen needs associated with critical illness. This may require invasive hemodynamic monitoring and pharmacologic support. Gas exchange in the lungs must be maintained without compromising cardiovascular function or exhausting the patient. Patients should be kept warm, pain free, and calm. Intravascular volume and the composition of the extracellular fluid must be maintained. Nutritional support should be provided early in amounts sufficient to meet the patient's basal nutritional requirements and increased needs associated with the critical illness. If at all possible, some or all of this nutritional support should be provided via the gastrointestinal tract. The use of specialized nutrients or of agents designed to minimize the catabolism of critical illness or to enhance anabolism is an area of active investigation. The indications for these therapeutic strategies in the elderly should become clearer in the years ahead.

Echo Doppler diastolic function and exercise tolerance

OBJECTIVE

To investigate the possible association between Doppler left ventricular filling pattern and exercise capacity in a group of normotensives to severe hypertensive patients.

BACKGROUND

Invasive left ventricular filling indexes evaluated at rest are reported to be related to exercise capacity in heart failure. Whether exercise capacity is limited by abnormalities of left ventricular filling also in other less severe conditions is however unclear.

METHODS

Fifty-one subjects with normal to severely elevated blood pressure underwent a standard exercise test on cycle ergometer, negative for myocardial ischemia, and a complete echo Doppler evaluation showing a basal systolic function within normal limits.

RESULTS

Basal systolic function indexes were not significantly related to exercise duration. On the contrary, exercise duration was highly significantly correlated to the relative atrial contribution to left ventricular filling (0.001 < P < 0.05), in both the overall group and the two subgroups in whom exercise was interrupted because of fatigue (n = 30) or because of attaining target heart rate (n = 21). Significant correlations were also observed between exercise time and resting blood pressure, whereas no association with resting heart rate, age and body surface area was found. Exercise time also correlated to left ventricular mass and mass index but not to left ventricular volume. Multiple regression analysis showed that exercise tolerance was significantly related to diastolic blood pressure and left ventricular filling. Echo Doppler indexes of left ventricular filling are associated with exercise duration; left ventricular diastole could thus influence effort tolerance, not only in patients with cardiac insufficiency, but also in subjects with normal to elevated blood pressure levels and normal systolic function at rest.

Importance of an individually programmed atrioventricular delay at rest and on work capacity in patients with dual chamber pacemakers

Despite higher costs, expenditure, and the necessity of repeatedly reprogramming of dual chamber pacemakers, they are increasingly implanted to achieve an optimal work capacity. The influence of an individually programmed atrioventricular (AV) delay between 100-250 msec on physical work capacity in 12 patients (68 +/- 16 years) with dual chamber pacemakers implanted for high degree AV block was studied. During radionuclide ventriculography at rest the "optimal AV delay" with the maximal achieved left ventricular ejection fraction and the "most unfavorable AV delay" with the least achieved ejection fraction were determined. The ejection fraction at rest with the "optimal AV delay" was 51 +/- 14% and with the "most unfavorable AV delay" 45 +/- 15% (P < 0.001). In random order each patient was assigned to either AV delay and a spiroergometry was performed to determine maximum oxygen uptake (max VO2), which correlates best with work capacity, at a respiratory quotient of 1.1. The results show neither a difference in maximum oxygen uptake (1,262 +/- 446 mL/min with the optimal AV delay, 1,248 +/- 400 mL/min with the most unfavorable AV delay, respectively) nor in heart rate, blood pressure, exercise duration, maximal workload, and minute ventilation. Thus, an individually programmed AV delay affects left ventricular ejection fraction at rest. In contrast, an individually programmed AV delay has no influence on physical work capacity in patients with a dual chamber pacemaker.

The use of transcranial Doppler in the hemodynamic assessment of implanted pacemakers

Twenty patients with DDD pacemakers had their intracranial cerebral circulation assessed in different pacing modes, using transcranial Doppler. The studies were performed at the vertebral artery in a sitting position. Although DDD pacing was preferred to VVI pacing in 18 of the 20 patients, the figures did not reach statistical significance. There was no statistical difference in maximal blood flow velocity between DDD pacing at 60 and 80 beats/min. Varying the AV interval from 150-250 msec also demonstrated no clear difference in maximal peak Doppler velocity, in the group as a whole, though there was a greater individual preference for 150 msec. Transcranial Doppler assessment of the hemodynamics of the cerebral circulation is of limited value as an indicator of mode or rate preference in the pacemaker population.

Doppler echocardiographic assessment of left ventricular filling in idiopathic dilated cardiomyopathy during a one-year follow-up: relation to the clinical course of disease

In idiopathic dilated cardiomyopathy (IDC), an impaired left ventricular filling as assessed by the Doppler echocardiographic mitral flow pattern is closely related to the severity of congestive heart failure. This study examined the relation of left ventricular filling and the clinical course of the disease in patients with a recent diagnostic procedure and initiation of medical therapy (group 1, n = 15) as compared with patients in a chronic stage of the disease (group 2, n = 24) with the diagnosis established > 1 year before. All patients had to be in sinus rhythm to facilitate the Doppler echocardiographic evaluation of left ventricular filling. The clinical status was assessed by the New York Heart Association classification and a heart failure score at baseline and after a period of 12 +/- 7 months. At baseline the ratio of the peak early/atrial Doppler velocities (VE/VA) was shifted toward the early diastole in group 1 as compared to group 2 (1.84 +/- 1.02 vs 1.12 +/- 0.55; p < 0.05). Symptoms of heart failure were more severe in group 1. During follow-up, VE/VA tended to decrease in group 1 from 1.84 +/- 1.02 to 1.35 +/- 1.03 (p = 0.07) and remained unchanged in group 2 (1.12 +/- 0.55 and 1.34 +/- 1.23; not significant). In a subgroup of 10 patients who underwent repeat right heart catheterization, the decrease of VE/VA coincided with a decrease of the pulmonary capillary wedge pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

Impact of heart rate and PR interval on Doppler indexes of left ventricular diastolic filling in an elderly cohort (the Framingham Heart Study)

The relations of heart rate and PR interval to Doppler-derived diastolic indexes were examined in 260 men (mean age 75 years) and 462 women (mean age 76 years) from the Framingham Heart Study. Subjects receiving any antihypertensive or cardiac medications were excluded from eligibility; those with mitral stenosis or prosthesis, pacemaker, atrial fibrillation, arrhythmia, left bundle branch block, congestive heart failure, previous myocardial infarction, and technically inadequate Doppler study were also excluded. Peak velocity of early (E) and late (A) diastolic left ventricular (LV) filling, ratio of peak velocities E/A, ratio of time velocity integrals E/A, and atrial filling fraction were studied by multivariable analyses adjusting for age, sex, blood pressure, heart rate and PR interval. Heart rate was a major determinant of all 5 Doppler indexes of diastolic filling; heart rate was inversely associated with peak velocity E, E/A, and time velocity integral E/A, and was directly associated with peak velocity A and atrial filling fraction. PR interval was inversely associated with time velocity integral E/A (p < 0.01) and directly associated with atrial filling fraction. The results were largely unaltered after further adjustment for LV wall thickness, LV end-diastolic diameter and left atrial diameter (in addition to age, sex and blood pressure). Heart rate and PR interval are independent contributors to Doppler-assessed LV diastolic filling in the elderly. The atrial contribution to LV filling depends on its timing in the cardiac cycle and on heart rate. Failure to account for heart rate and PR interval may lead to inappropriate assessment of Doppler diastolic filling.

Transesophageal Doppler echocardiographic assessment of pulmonary venous flow pattern in subjects without cardiovascular disease

This study was designed to assess pulmonary venous flow dynamics using transesophageal Doppler echocardiography. Under general anesthesia, we studied 54 surgical patients with no history or physical evidence of cardiac disorders. In all patients pulmonary venous flow was easily identified by transesophageal color flow mapping. Pulmonary venous flow pattern, which was obtained clearly in 85% (4654) of patients by transesophageal pulsed Doppler echocardiography, was tri- or quadriphasic. The first wave, which was often biphasic in elderly patients, occurred during ventricular systole (S wave). The second wave occurred in diastole during the early ventricular filling phase of mitral flow (D wave). The third wave was reverse flow toward the pulmonary vein during atrial contraction (A wave). The following variables were measured: the peak flow velocities of each wave (PFVs, PFVd, PFVa), and the ratio of PFVs to PFVd (PFV(S/D)). The PFVd correlated with age (r = -0.56, P < 0.001), indicating age-related decrease. The PFV(S/D) correlated with age (r = 0.61, p < 0.001), indicating age-related increase. These results would indicate that the contribution of pulmonary venous flow during diastole to total pulmonary venous flow decreases with age. Our data suggest that age-related diastolic dysfunction of the left ventricle would affect pulmonary venous flow dynamics and that left atrial storage volume during ventricular systole would increase with age.

Age-related changes in left and right ventricular filling velocity profiles and their relationship in normal subjects

To confirm age-related changes in left and right ventricular filling velocity profiles and to compare left and right ventricular filling parameters in normal subjects, we performed pulsed Doppler echocardiographic studies in 108 normal subjects (72 men and 36 women) aged 15 to 78 years. An age-related decrease in peak early velocity (E velocity), an increase in peak atrial velocity (A velocity), and augmented ratio of A velocity to E velocity (A/E) were observed in left ventricle (r = -0.71, 0.63, and 0.83, respectively). Similar age-related changes were found in right ventricle (r = -0.71, 0.54, and 0.78). Aging had a greater effect on the filling of the left ventricle than the right one (i.e., a steeper slope). The difference between left and right ventricular filling increased with advancing age. Left ventricular filling indexes exceeded those of the right ventricle. Significant correlations were observed between the right and left ventricular filling parameters (r = 0.58 to 0.90). A strong relation was noted in A/E (r = 0.90). There was no significant relation between age and left ventricular mass. The left ventricular mass appeared to have little effect on left and right ventricular filling in normal individuals. Thus in clinical studies the age-related decrease in early diastolic filling and the increased atrial filling in both left and right ventricles should be considered. The atrial contribution to ventricular filling may be more pronounced in the left ventricle than the right ventricle in older subjects.

Time-course of recovery of atrial contraction after cardioversion of chronic atrial fibrillation

We aimed to study the time-course of recovery of atrial contraction after cardioversion of chronic atrial fibrillation (duration of more than 3 months) to sinus rhythm. Using M-mode, two-dimensional and pulsed Doppler echocardiography, we determined left atrial (LA) and ventricular (LV) dimensions, peak velocities, and velocity-time integrals of early and atrial filling velocity-time profiles in both LV and right ventricular (RV) inflows (peak E and peak A, Ea and Aa). Results of the LA and LV functions in seven elderly patients (an initial study group) were as follows. The extent of the LA dimensional reduction resulting from atrial contraction was significantly increased up to 5-8 weeks compared with values 0-1 day after cardioversion [from 1.3 +/- 0.8 (mean +/- SD) mm to 3.9 +/- 1.1, P < 0.01]. In conjunction with the progressive increase in peak A, the ratio of peak E to peak A (peak E/A) was significantly decreased and reached a plateau at 5-8 weeks (from 1.93 +/- 0.59 to 0.67 +/- 0.11, P < 0.01). LV fractional shortening was increased significantly 5-8 weeks after cardioversion (from 0.20 +/- 0.06 to 0.29 +/- 0.05, P < 0.01). Since a large part of the improvement in LA contraction was expected to occur in an early stage after cardioversion, we studied eight additional patients more frequently in the early stage (an additional study group). Furthermore, we studied the time course of LA and right atrial (RA) contractions.(ABSTRACT TRUNCATED AT 250 WORDS)

Impaired left ventricular filling in borderline hypertensive patients without cardiac structural changes

To determine the effect of borderline hypertension on left ventricular diastolic performance, 16 patients with borderline hypertension who did not have left ventricular hypertrophy and 16 age-sex-matched patients with normotension of similar age and body mass index were investigated. Pulsed Doppler echocardiography was used to record left ventricular filling signals at rest and immediately after supine ergometer exercise. All subjects had normal left ventricular structure and systolic function. At rest the borderline hypertension group in comparison with the normotension group had a depressed peak velocity of early filling (E) (44 +/- 7 vs 54 +/- 10 cm/sec; p < 0.01), no enhanced peak velocity of late filling (A) (52 +/- 8 vs 50 +/- 11 cm/sec; not significant), and a reduced E/A ratio (0.9 +/- 0.2 vs 1.1 +/- 0.3; p < 0.05). Atrial filling time and preejection period were similar in the two groups. The effect of exercise on left ventricular filling velocity in patients with borderline hypertensive resembled that in those with normotension. Percentage changes in E (+14% +/- 12% vs +14% +/- 13%) and A (+13% +/- 8% vs 11% +/- 12%) were equivalent, suggesting a preserved diastolic reserve for exercise in the borderline hypertension group. In conclusion, borderline hypertension appears to be predictive of early filling impairment, and a late filling compensative mechanism is not yet apparent. These findings in borderline hypertension without apparent cardiac damage call for clinical attention to prevent further deterioration in cardiac function.

Isovolumetric relaxation flow in patients with ischemic heart disease

OBJECTIVES

The purpose of this study was to clarify the characteristics of flow during the isovolumetric relaxation period and to analyze the relation between these flow patterns and standard hemodynamic indexes.

BACKGROUND

Outward motion of the left ventricle during the isovolumetric relaxation period has been observed by cineangiography. However, there is little information about blood flow during this period.

METHODS

Seventy-nine patients with ischemic heart disease were examined by pulsed Doppler echocardiography and cardiac catheterization. All patients were classified into three groups according to the observed patterns of isovolumetric relaxation flow: group I (n = 41), flow directed toward the apex; group II (n = 21), flow directed toward the base, and group III (n = 17), low velocity flow (< 12 cm/s) without a dominant direction. Patients in group I were further classified into group Ia (n = 19) with normal ventriculograms and group Ib (n = 22) with asynergy.

RESULTS

Left ventricular ejection fraction and negative first derivative of left ventricular pressure were significantly lower in group II (49 +/- 9% and 1,274 +/- 212 mm Hg/s, respectively) and group III (38 +/- 8% and 1,147 +/- 280 mm Hg/s, respectively) than in group Ia (68 +/- 7% and 1,727 +/- 358 mm Hg/s), each p < 0.01. Time constant was significantly prolonged in group II (49 +/- 6 ms) and group III (48 +/- 6 ms) compared with that in group Ia (41 +/- 6 ms), p < 0.05. On left ventriculography, patterns of outward wall motion during the isovolumetric relaxation period were associated with the patterns of isovolumetric relaxation flow.

CONCLUSIONS

Changes in left ventricular relaxation are accompanied by alterations in isovolumetric relaxation flow. It is therefore useful to evaluate isovolumetric relaxation flow when investigating early diastolic ventricular function.

Pitfalls in the echo-Doppler assessment of diastolic dysfunction

The Doppler echocardiographic assessment of diastolic function is an essential part of the evaluation of heart failure, pericardial diseases, restrictive and infiltrative cardiomyopathies, and many other conditions. However, the echocardiographic evaluation of diastolic function has several limitations. The sonographer and physician must understand the technical factors, the effects of physiological and pathophysiological conditions, and the dynamics of pseudonormalization, all of which affect the evaluation. This article will review the most recent data essential for the proper performance and interpretation of a transthoracic or transesophageal Doppler echocardiographic examination of diastolic function.

Relation of left ventricular isovolumic relaxation time and incoordination to transmitral Doppler filling patterns

OBJECTIVE

To investigate factors during isovolumic relaxation that determine Doppler filling patterns in patients with left ventricular disease, and thus to identify the underlying mechanisms.

DESIGN

85 patients (50 ischaemic heart disease, 35 left ventricular hypertrophy due to aortic stenosis) and 26 controls were studied with Doppler and M mode echocardiography and phonocardiography. 16 patients underwent two studies on separate occasions, to find whether changes in isovolumic relaxation time were reflected by a change in the Doppler A/E ratio.

SETTING

A tertiary cardiac referral centre.

SUBJECTS

Patients referred for assessment of coronary artery disease or aortic stenosis with left ventricular hypertrophy.

MAIN OUTCOMES MEASURES

Doppler filling velocities during early (E wave) and late (A wave) diastole and the A/E ratio, acceleration of the E wave, digitised M mode indices of incoordinate relaxation (change in cavity dimension before mitral valve opening and time from minimum dimension to mitral valve opening), isovolumic relaxation time, M mode measures of diastolic function after mitral valve opening (peak rate of posterior wall thinning and peak rate of dimension increase), and left ventricular end diastolic pressure.

RESULTS

A/E correlated with age in normal subjects (r = 0.74), to a lesser extent in left ventricular hypertrophy (r = 0.41), but not significantly in ischaemic heart disease. In all patients, isovolumic relaxation time was significantly and negatively correlated with the acceleration of the E wave, showing its fundamental relation to the force responsible for early diastolic filling (r = -0.71 for left ventricular hypertrophy, and -0.74 for ischaemic heart disease, p value < 0.01). In left ventricular hypertrophy and those ischaemic patients without left ventricular dilatation A/E was correlated both with isovolumic relaxation time (r = 0.68 and 0.60 respectively), and with incoordinate relaxation (r = 0.65 and 0.61). In those ischaemic patients with left ventricular dilatation, the influence of incoordination was lost and isovolumic relaxation time became the dominant influence upon A/E (r = 0.82). Weak correlations of end diastolic pressure and RR interval with A/E, became insignificant once isovolumic relaxation time had been taken into account. Isovolumic relaxation time and incoordination together accounted for over 50% of the variance in the A/E ratio in our patients. Isovolumic relaxation time and the A/E ratio were linearly related. Patients with a short isovolumic relaxation time had evidence of considerable diastolic abnormalities, despite a normal Doppler A/E ratio. In the 16 patients who had two echocardiographic studies, changes in the duration of isovolumic relaxation were accompanied by a change in the Doppler A/E ratio. The relation between these two variables, derived from the group as a whole was similar.

CONCLUSIONS

The main factors influencing the A/E ratio in patients with left ventricular disease are two distinct properties of isovolumic relaxation--namely the duration and the extent of incoordinate wall motion. Filling pressure and RR interval are not significant independent determinants, but act only through an effect upon isovolumic relaxation time. Age is an important influence in normal people, but this effect is attenuated in left ventricular hypertrophy and lost in ischaemic ventricular disease.

Adjustment for the influence of age and heart rate on Doppler measurements of left ventricular filling

OBJECTIVE

To determine the normal range of pulsed Doppler measurements of left ventricular filling adjusted for age and heart rate.

DESIGN

Multiple regression was used to measure the effects of age and heart rate on pulsed Doppler indices of left ventricular filling in normal subjects. These regression equations were used to calculate a predicted normal value and 95% confidence interval (95% CI) for any subject from his age and heart rate.

PARTICIPANTS

61 subjects with no evidence of cardiovascular disease, aged 20 to 90 years, with a resting heart rate of 47-89 beats/min.

RESULTS

The effect of a 10 year increase in age was peak atrial filling velocity +15% (95% CI 12.0% to 18.5%); peak early filling velocity -3.2% (-6.0% to 0%); isovolumic relaxation time +6.2% (3.9% to 8.4%); acceleration time -3.8% (-6.0% to -1.5%); deceleration time +7.9% (5.1% to 10.8%). The effect of a 10 beat/min increase in heart rate was: peak atrial filling velocity +5.5% (1.2% to 10.1%); peak early filling velocity -4.0% (-8.1% to 2.0%); isovolumic relaxation time -2.5% (-4.6% to 0.6%); acceleration time -3.1% (-6.4% to 0.4%); deceleration time -1.8% (-4.0% to 3.8%).

CONCLUSION

For any individual, comparison of the predicted normal measurement and 95% CI with the observed measurement allows an assessment of the effects of disease on left ventricular filling that is independent of age and heart rate.

Doppler evaluation of normalized peak filling rate in normal children and children with left ventricular outflow obstruction

To evaluate the early diastolic peak filling rate of the left ventricle, three groups of children (normal children, patients with aortic valvular stenosis, and patients with aortic coarctation) were examined with the peak filling rate normalized to stroke volume calculated from the mitral valve inflow Doppler recording as the peak E velocity divided by the velocity time integral. The normal value for this index in children was 6.78 +/- 0.99 SV/sec and did not vary with age, weight, body surface area, or heart rate. Compared with normal subjects, both patients with aortic stenosis and patients with coarctation had increased left ventricular mass, but patients with aortic stenosis had decreased normalized peak filling rates (5.3 +/- 0.84 SV/sec, p < 0.01), while patients with coarctation had normal rates (6.79 +/- 0.98 SV/sec, p = 0.97). Compared with patients with aortic coarctation, patients with aortic stenosis had higher Doppler gradients. Thus the Doppler index of peak filling rate normalized to stroke volume is particularly useful in children because it is independent of heart rate, age, weight, and body surface area. Patients with coarctation may have normal peak filling rates normalized to stroke volume despite increased left ventricular mass because of milder obstruction or better coronary artery perfusion compared with that of patients with aortic stenosis.

Age-related increase in systolic fraction of pulmonary vein flow velocity-time integral from transesophageal Doppler echocardiography in subjects without cardiac disease

The pulmonary vein flow velocity-time profile would be equivalent to the pulmonary vein flow volume-time profile, provided that the cross-sectional area of the pulmonary vein remains unchanged during 1 cardiac cycle. The systolic fraction of the pulmonary vein flow velocity-time integral, a ratio of velocity-time integral of the S wave to the sum of velocity-time integrals of the S and D waves, represents the ratio of left atrial storage volume to left ventricular stroke volume. This systolic fraction may help early filling of the left ventricle through an appropriate storage of blood and generation of driving pressure in the left atrium. Because early filling of the left ventricle is progressively impaired with age, it was hypothesized that this systolic fraction is increased with age. Forty-four noncardiac surgical patients (age range 17 to 70 years) who underwent transesophageal Doppler echocardiography under general anesthesia were studied, and left upper pulmonary vein flow and mitral inflow velocities were recorded. The ratio of peak velocity of the E wave to that of the A wave of mitral inflow velocity-time profile (y) decreased with age (y = -0.0245 x age + 2.41; r = -0.672, p < 0.01). Systolic fraction (y) increased with age (y = 0.00373 x age + 0.514; r = 0.656, p < 0.01). The age-related increase in the systolic fraction of pulmonary vein flow velocity-time integral may account for the compensation for impaired early filling of the left ventricle in elderly patients.

Influence of left ventricular filling profile on the effect of atrioventricular synchronous pacing

We correlated the percentage of atrial contribution to left ventricular filling (percent AC) assessed by Doppler echocardiography with the hemodynamic benefit from atrioventricular synchronous pacing assessed by direct hemodynamic measurements. Subjects comprised 40 patients who underwent electrophysiologic catheterization because of unexplained syncope or bradycardia (< 40 beats/min). Femoral arterial and pulmonary capillary wedge pressure were recorded by catheterization, and cardiac output was measured by thermodilution during temporary atrioventricular synchronous (DDD, 70 beats/min with 150 ms of atrioventricular delay) and ventricular (VVI, 70 beats/min) pacing. Mitral inflow velocity by pulsed-wave Doppler echocardiography was recorded during DDD pacing and percent AC was obtained by calculating the ratio of mitral inflow velocity area during atrial systole to total mitral inflow velocity area during early diastole and atrial systole. The mean arterial pressure and the cardiac output increased significantly (99 +/- 16 mm Hg vs 90 +/- 15 mm Hg, p < 0.001; 4.6 +/- 1.0 L/min vs 3.9 +/- 0.9 L/min, p < 0.001), and the mean pulmonary capillary wedge pressure decreased (7 +/- 4 mm Hg vs 10 +/- 4 mm Hg, p < 0.001) during DDD compared with VVI pacing. A significant positive correlation was observed between the percent AC and the increase in cardiac output (r = 0.58, n = 40, p < 0.01) or the increase in mean arterial pressure (r = 0.62, n = 38, p < 0.01) during DDD pacing. The percent AC did not significantly correlate with the decrease in pulmonary capillary wedge pressure. In conclusion, patients with larger percent AC may receive major benefit from atrioventricular synchronous pacing.

Variability between current definitions of 'normal' ambulatory blood pressure. Implications in the assessment of white coat hypertension

The assessment of white coat hypertension is complicated by the lack of generally agreed-on normal limits of ambulatory blood pressure. To assess the influence of four of these limits on the prevalence of white coat hypertension and the corresponding distribution of left ventricular hypertrophy, we performed 24-hour ambulatory blood pressure monitoring and echocardiographic studies in 346 untreated patients with essential hypertension and 47 age-matched normotensive control subjects. The upper limits of normal daytime ambulatory blood pressure were lower using standards drawn from clinically normotensive populations than using standards drawn, partly or entirely, from general populations. The prevalence of white coat hypertension differed markedly using the different standards, being 12.1%, 16.5%, 28.9%, and 53.2% (chi 2 = 346.0, p less than 0.0001). Left ventricular mass index averaged 77 g/m2 in the control group, 85 g/m2 in the two groups with white coat hypertension defined by using standards drawn from normotensive populations (both comparisons not significant versus control group), and 90 and 98 g/m2 in the two groups with white coat hypertension defined by using the other two standards (both p less than 0.01 versus control group). The prevalence of echocardiographic left ventricular hypertrophy was 0% in the control group, 2.4% and 3.5% in the two groups with white coat hypertension defined by using standards drawn from normotensive populations, and 9.0% and 14.7% in the other two groups with white coat hypertension (p less than 0.05 and p less than 0.01, respectively, versus control group).(ABSTRACT TRUNCATED AT 250 WORDS)