Left ventricular mass and systolic performance in chronic systemic hypertension

Investigation of Acoustic Cardiographic Parameters before and after Hemodialysis

Patients with end-stage renal disease are at an increased risk of cardiovascular diseases and associated mortality. Acoustic cardiography is a technique in which cardiac acoustic data is synchronized with electric information to detect and characterize heart sounds and detect heart failure early. The aim of this study was to investigate acoustic cardiographic parameters before and after hemodialysis (HD) and their correlations with ankle-brachial index (ABI), brachial-ankle pulse wave velocity (baPWV), and ratio of brachial preejection period to ejection time (bPEP/bET) obtained from an ABI-form device in HD patients. This study enrolled 162 HD patients between October 2016 and April 2018. Demographic, medical, and laboratory data were collected. Acoustic cardiography was performed before and after HD to assess parameters including third heart sound (S3), fourth heart sound (S4), systolic dysfunction index (SDI), electromechanical activation time (EMAT), and left ventricular systolic time (LVST). The mean age of the enrolled patients was 60.4 ± 10.9 years, and 86 (53.1%) patients were male. S4 (p < 0.001) and LVST (p < 0.001) significantly decreased after HD, but EMAT (p < 0.001) increased. Multivariate forward linear regression analysis showed that EMAT/LVST before HD was negatively associated with albumin (unstandardized coefficient β = ‐0.076; p = 0.004) and ABI (unstandardized coefficient β = ‐0.115; p = 0.011) and positively associated with bPEP/bET (unstandardized coefficient β = 0.278; p = 0.003). Screening HD patients with acoustic cardiography may help to identify patients at a high risk of malnutrition, peripheral artery disease, and left ventricular systolic dysfunction.

A review of heart chamber segmentation for structural and functional analysis using cardiac magnetic resonance imaging

Cardiovascular magnetic resonance (CMR) has become a key imaging modality in clinical cardiology practice due to its unique capabilities for non-invasive imaging of the cardiac chambers and great vessels. A wide range of CMR sequences have been developed to assess various aspects of cardiac structure and function, and significant advances have also been made in terms of imaging quality and acquisition times. A lot of research has been dedicated to the development of global and regional quantitative CMR indices that help the distinction between health and pathology. The goal of this review paper is to discuss the structural and functional CMR indices that have been proposed thus far for clinical assessment of the cardiac chambers. We include indices definitions, the requirements for the calculations, exemplar applications in cardiovascular diseases, and the corresponding normal ranges. Furthermore, we review the most recent state-of-the art techniques for the automatic segmentation of the cardiac boundaries, which are necessary for the calculation of the CMR indices. Finally, we provide a detailed discussion of the existing literature and of the future challenges that need to be addressed to enable a more robust and comprehensive assessment of the cardiac chambers in clinical practice.

Estimated Glomerular Filtration Rate and Systolic Time Intervals in Risk Stratification for Increased Left Ventricular Mass Index and Left Ventricular Hypertrophy

Either decreased renal function or increased systolic time interval is associated with cardiac hypertrophy and poor cardiac outcome. The aim of this study was to evaluate combination of renal function and brachial systolic time intervals were associated with increased left ventricular mass index (LVMI) and left ventricular hypertrophy (LVH).In total of 990 patients were consecutively included in this study from January 2011 to December 2012. All study participants were further classified into 4 groups by the values of estimated glomerular filtration rate (eGFR) and ratio of brachial preejection period (bPEP) to brachial ejection time (bET). The classification of 4 groups were eGFR ≥ 45 mL/min/1.73 m and bPEP/bET < 0.38 (group 1), eGFR ≥ 45 ml/min/1.73 m and bPEP/bET ≥ 0.38 (group 2), eGFR < 45 mL/min/1.73 m and bPEP/bET < 0.38 (group 3), and eGFR < 45 mL/min/1.73 m and bPEP/bET ≥ 0.38 (group 4), respectively. Patients in groups 1 and 4 had the lowest and highest LVMI among 4 groups, respectively (P < 0.001). In multivariable analyses, increased LVMI and LVH were significantly associated with patients in groups 2, 3 and 4 (vs group 1) (P ≤ 0.019).Our study demonstrated that joined parameter of renal function and systolic time intervals, in terms of eGFR and bPEP/bET, might be an alternative method in risk stratification for increased LVMI and LVH.

Association of brachial-ankle pulse wave velocity, ankle-brachial index and ratio of brachial pre-ejection period to ejection time with left ventricular hypertrophy

BACKGROUND

Arterial stiffness, peripheral artery disease and left ventricular systolic dysfunction contributed to left ventricular hypertrophy (LVH). Using an ABI-form device, we can obtain brachial-ankle pulse wave velocity (baPWV), ankle-brachial index (ABI) and the ratio of brachial pre-ejection period to ejection time (bPEP/bET), which are markers for arterial stiffness, peripheral artery disease and left ventricular systolic function, respectively. The aim of this study was to assess whether "BAP score" calculated from the 3 measures of baPWV, ABI and bPEP/bET is associated with LVH.

METHODS

A total of 1,146 patients were included in the study. BAP score was calculated based on a point system in which 1 point was assigned for baPWV above the median value of 1670 cm/s, ABI < 0.9 or ≥ 1.3 in either leg and bPEP/bET > 0.38.

RESULTS

There was a significant trend for a stepwise increase in the left atrial diameter, left ventricular mass index (LVMI) and the prevalence of LVH and a stepwise decrease in the left ventricular ejection fraction corresponding to advancement in BAP score from 0 to 3. In addition, increased BAP score is significantly associated with increased LVMI and LVH.

CONCLUSIONS

Our results demonstrated increased BAP score was related to increased LVMI and LVH independent of traditional risk factors such as old age, diabetes, hypertension, obesity, anemia, hyperlipidemia and chronic kidney disease. Therefore, the BAP score obtained from the same examination might be useful and convenient in identifying patients with increased LVMI and LVH.

Impact of systolic time intervals on the relationship between arterial stiffness and left ventricular hypertrophy

OBJECTIVES

Arterial stiffness is correlated with left ventricular hypertrophy (LVH) and is susceptible to left ventricular performance. Therefore, if left ventricular systolic function is unknown, the relationship between arterial stiffness and LVH is controversial. This study was to assess the impact of the ratio of brachial pre-ejection period (bPEP) to brachial ejection time (bET), a marker of left ventricular systolic function, on the relationship between brachial-ankle pulse wave velocity (baPWV) and LVH.

METHODS

A total of 1146 patients were included in the study. The baPWV and bPEP/bET were measured using an ABI-form device. Patients were classified into four groups. Groups 1, 2, 3, and 4 were patients with bPEP/bET ≤ 0.38 and baPWV below the median, bPEP/bET > 0.38 but baPWV below the median, bPET/bET ≤ 0.38 but baPWV above the median, and bPET/bET > 0.38 and baPWV above the median, respectively.

RESULTS

Patients in groups 3 and 4 (high baPWV) and patients in group 2 (low baPWV but high bPEP/bET) were associated with increased left ventricular mass index (LVMI) and LVH (all P < 0.001). In a multivariate model, baPWV was significantly associated with LVMI (P = 0.007) and LVH (P = 0.025). Further adjustment for bPEP/bET made the association between baPWV and LVMI (P = 0.150) and LVH (P = 0.173) disappear.

CONCLUSIONS

The bPEP/bET has an important impact on the relationship between baPWV and LVH. Therefore, the value of bPEP/bET obtained from the same examination should be considered while interpreting the relationship between baPWV and LVH.

Assessment of left ventricular myocardial performance by tissue Doppler echocardiography in patients with polycythemia vera

AIMS

The aim of this study was to evaluate myocardial performance index (MPI) which reflects the combined systolic and diastolic performance of the ventricles by tissue Doppler imaging (TDI) in patients with polycythemia vera (PV).

METHOD AND MATERIALS

Twenty-eight patients with PV (17 men; mean age 60±9 years) and 30 age-matched healthy subjects were prospectively evaluated. The diagnosis of PV was performed according to the World Health Organization (WHO) criteria. Left ventricular (LV) systolic and diastolic functions were assessed by conventional echocardiography and TDI. MPI of both the LV and right ventricles (RV) were measured by TDI method.

RESULTS

The LV MPI was significantly higher in PV group than in the controls (0.61±0.16 vs. 0.49±0.05; P=0.001). Also, the RV MPI was impaired in patients with PV compared to the control subjects (0.51±0.11 vs. 0.43±0.09; P=0.005). RV late A filling velocity (Am) and RV isovolumetric relaxation time were significantly higher in the PV group compared to healthy subjects (P=0.03 and 0.05, respectively). In logistic regression models, PV was determined as an independent predictor of impaired MPI (odds ratio: 3.7; CI 95%, 1.2-7.5). In addition, pulmonary arterial pressure was significantly elevated in patients with PV compared to the controls (P=0.02).

CONCLUSION

This study demonstrated that biventricular MPI is impaired in patients with PV.

Cardiovascular effects of type 1 diabetes mellitus in children

Previous studies have shown that type 1 diabetes mellitus (DM) is associated with cardiovascular abnormalities. Early detection and treatment of these abnormalities may help to prevent the natural progression of the disease. The present study was undertaken to define early cardiovascular abnormalities in children with type 1 DM. Simultaneous evaluation of multiple cardiovascular parameters was performed in 14 children with type 1 DM and 14 age-and gender-matched normal subjects. Measurements of carotid artery intima-media thickness (cIMT, echocardiography), carotid and aortic (ascending and abdominal) distensibility (echocardiography, brachial artery blood pressure), aortic pulse wave velocity (carotid to femoral artery, Doppler), and left ventricular dimensions, mass, and function (echocardiography) were performed. Diabetic children demonstrated a greater cIMT (0.36 +/- 0.04 mm vs 0.31 +/- 0.03 mm, p = 0.002) and decreased carotid artery distensibility (4.4 +/- 1.6 cm(2) . dynes(-1) . 10(-6) vs 6.0 +/- 1.9 cm(2) . dynes(-1) .10(-6), p < 0.01) compared to control. Aortic pulse wave velocity was increased in DM (6.70 +/- 0.39 vs 6.30 +/- 0.31, p = 0.02) compared to control. Left ventricular diameters, mass, and systolic and diastolic function did not differ between the 2 groups. Simultaneous assessment of multiple cardiovascular parameters in children with type 1 DM revealed impaired carotid artery structure and function, and decreased elastic properties of the aorta, before demonstrable changes in left ventricular structure and function could be detected.

Inadequate management of cerebrovascular risk factors in participants of a public stroke prevention program in Austria

The aim of our investigation was to identify frequencies and treatment quality of stroke risk factors in participants of a stroke prevention program in the province of Salzburg (Austria). A total of 9356 participants free of previous stroke were classified in three risk categories for suffering from ischemic stroke within the next 10 years and analyzed referring to history, therapy, and treatment quality of cerebrovascular risk factors. A total of 6519 (69.7%) participants were classified to be at low (<10%), 2232 (23.9%) at intermediate (10-20%) and 605 (6.5%) at high risk (>20%). Elevated blood pressure with the need for follow-up investigations was found in 5193 persons (55.5%); of 3713 (39.7%) persons with a history of hypertension, 3204 (86.3%) are under medical treatment, which is sufficient only in 765 patients (23.9%). Similar results were present for other well documented modifiable risk factors. In the investigated population there is high presence of stroke risk factors with inadequate treatment in most cases.

Acute changes in preload, afterload, and systolic function after superior cavopulmonary connection

BACKGROUND

Superior cavopulmonary connection reduces the volume work of the single ventricle.

METHODS

To determine the effects of superior cavopulmonary connection on preload, wall stress (or afterload), and systolic ventricular function, we studied 9 patients before and after operation, and at hospital discharge. Using echocardiography, preload was estimated by the ventricular end-diastolic area, and wall stress was calculated at end-systole and peak-systole. Ventricular function was represented by rate-corrected velocity of circumferential fiber shortening and fractional area change divided by rate-corrected ejection time.

RESULTS

End-diastolic area and wall stress decreased postoperatively. Ventricular wall thickness increased with a concomitant decrease in cavity area. There was no change in mean blood pressure or heart rate or in rate-corrected velocity of circumferential fiber shortening or fractional area change divided by rate-corrected ejection time. These findings persisted at hospital discharge.

CONCLUSIONS

In single ventricles, superior cavopulmonary correction results in an immediate decrease in preload and afterload. The decrease in afterload results primarily from alterations in ventricular geometry. Although no improvement in systolic function was noted, diminished work related to the reduction in loading conditions may have beneficial long-term effects on preserving myocardial performance.

Is blood pressure the major determinant of left ventricular mass in subjects over 50 years of age?

The weak relation of systolic blood pressure to left ventricular (LV) mass in hypertension has frequently been regarded as evidence of non-hemodynamic stimuli to muscle growth. Anyway, left ventricular hypertrophy (LVH) is associated with a significantly increased risk for cardiovascular events. Data were obtained from M-mode echocardiograms in 10 normotensives and 58 hypertensives over 50 years (range 50-85 years); 18 hypertensives; were without (LVH -) and 40 were with LVH (LVH +) - when LV mass, normalized for body surface area, was calculated according to the Penn's Convention. Cardiac output was derived by Teicholz formula for LV volumes. End-systolic stress/end-systolic dimension ratio (ESS/ ESD r), an index of myocardial contractility, was calculated as previously validated in the literature. We found that, in subjects ranging from 50 to 85 years of age, the presence of LV hypertrophy is not necessarily associated with raised blood pressure levels. Systolic function was substantially preserved among the study groups, irrespective of their age, hypertensive condition and/or presence of LVH. The increased wall thickness in subjects with LVH was associated with a significant reduction in wall stress (thus suggesting an adequateness of the compensatory role of LVH - at least at the observed stage of the hypertrophy process) and with a significant decrease of the contractile performance. On the multivariate analysis, the observed relation of LV mass to blood pressure and myocardial contractility (r = 0.621, P < 0.001) may explain some apparently conflicting findings, such as the lack of LV hypertrophy in a number of hypertensive patients.

Effect of quinapril or metoprolol on heart rate variability in post-myocardial infarction patients

The effect of quinapril or metoprolol on heart rate variability (HRV) indexes was studied in patients who had recovered from acute myocardial infarction. Patients with stable coronary artery disease and normal volunteers were used as controls. Sixty patients with uncomplicated myocardial infarction (aged 32 to 74 years [mean 56.7]) were randomized to quinapril (n = 25), metoprolol (n = 25), and placebo (n = 10). HRV was assessed 5 days (baseline) and 35 days after the onset of acute myocardial infarction. After the baseline studies, the post-myocardial infarction patients were treated with metoprolol (50 to 100 mg/day), quinapril (5 to 10 mg/day), or placebo. Twenty patients with stable coronary artery disease and 20 healthy volunteers, age- and sex-matched to myocardial infarction patients, were used as controls. Compared with placebo, quinapril and metoprolol increased HRV indexes significantly 35 days after the onset of myocardial infarction. HRV indexes were not statistically different between the 2 treatment groups. At baseline and after therapy, HRV was similar in patients with anterior or inferior wall myocardial infarction. HRV 35 days after the onset of myocardial infarction was not different from HRV in patients with stable coronary artery disease, but was decreased when compared with that in normal volunteers. Data suggest that quinapril has the same beneficial effect on HRV indexes as metoprolol in patients who have recovered from uncomplicated acute myocardial infarction.

Left atrial volumes and function in orthotopic cardiac transplantation

Early ventricular filling and therefore passive left atrial emptying may be impaired in patients with cardiac transplantation. As a result, left atrial function may be an important factor in maintaining stroke volume in recipients of orthotopic cardiac transplants. Left atrial volumes maximal (mitral valve opening), minimal (mitral valve closure), and onset of atrial systole (P wave on electrocardiogram) were determined by echocardiography using the biplane area-length method in 12 patients after cardiac transplantation and 12 control subjects. Maximal and minimal left atrial volumes and left atrial volumes at onset of atrial systole were larger in patients who had cardiac transplantation than in control subjects (89.8 vs 41.8 cm3, 48 vs 15.2 cm3, and 70.4 vs 27.0 cm3, respectively; p < 0.01). In patients undergoing cardiac transplantation, good correlations were found between left atrial maximal volume and left ventricular mass (r = 0.56) and between left atrial maximal volume and mean pulmonary capillary wedge pressure (r = 0.81). Left atrial passive emptying volume (maximal minus volume at P wave), was not statistically different between the two groups (19.3 in patients receiving transplants vs 14.7 cm3 in control subjects), but left atrial stroke volume (beginning atrial systole to minimal) was larger in patients receiving transplants than in control subjects (22.4 vs 11.8 cm3, respectively; p < 0.001). Thus left atrial contraction contributed 42% to the left ventricular stroke volume in patients who had cardiac transplantation but only 17% in control subjects (p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiovascular manifestations of hypertension in children

Hypertension has its roots in childhood. Electrocardiographic, echocardiographic, and exercise testing in young patients point to early abnormalities of cardiovascular status in children with early hypertensive disease. Altered morphology of the cardiovascular system and vascular reactivity is also seen in the hypertensive or prehypertensive child. Perhaps investigation and preventive tactics may be best applied to the pediatric population.

Left ventricular midwall mechanics in systemic arterial hypertension. Myocardial function is depressed in pressure-overload hypertrophy

BACKGROUND

Left ventricular (LV) midwall geometry has been described conventionally as the sum of the chamber radius and half of the wall thickness; this convention is based on the assumption of uniform transmural thickening during systole. However, theoretical considerations and experimental data indicate that the inner half (inner shell) of the LV wall thickens more than the outer half (outer shell). Thus, an end-diastolic circumferential midwall fiber exhibits a relative migration toward the epicardium during systole. As a result, the conventional method provides an overestimate of the extent of the midwall fiber shortening.

METHODS AND RESULTS

We developed an ellipsoidal model with a concentric two-shell geometry (nonuniform thickening) to assess midwall fiber length transients throughout the cardiac cycle. This modified midwall method was used in the analysis of LV cineangiograms from 15 patients with systemic arterial hypertension and 14 normal subjects. Study groups were classified according to LV mass index (LVMI): 14 normal subjects (group I), eight hypertensive patients with a normal LVMI (group II), and seven hypertensive patients with an increased LVMI (group III). There were no significant differences in LV end-diastolic pressure or volume among the three groups; the ejection fraction was slightly greater in group II (70 +/- 5%) than in groups I (65 +/- 8%) and III (66 +/- 4%), but this trend did not achieve statistical significance. Values for endocardial and conventional midwall fractional shortening (FS) were also similar in the three groups. By contrast, FS by the concentric two-shell geometry (modified midwall method) in group III (16 +/- 2%) was significantly less than that seen in groups I and II (21 +/- 4% and 21 +/- 5%, respectively; both p less than 0.05). This difference achieves greater importance when it is recognized that mean systolic circumferential stress was lower in group III (151 +/- 22 g/cm2) than in groups I and II (244 +/- 37 g/cm2 and 213 +/- 38 g/cm2, respectively; both p less than 0.01). The midwall stress-shortening coordinates in six of the seven group III patients were outside the 95% confidence limits for the normal (group I) subjects. Thus, despite a normal ejection fraction, systolic function is subnormal in hypertensive patients with LV hypertrophy.

CONCLUSIONS

Chamber dynamics provide an overestimate of myocardial function, especially when LV wall thickness is increased. This is due to a relatively greater contribution of inner shell thickening in pressure-overload hypertrophy.

Casual, ambulatory and stress blood pressure: relationships with left ventricular mass and filling

In arterial hypertension, casual blood pressure seems to be weakly related to the level of cardiac involvement. The aim of the present study was to assess if blood pressure during ambulatory monitoring, and during different stress tests, is a stronger predictor of anatomical and functional changes observed in hypertensive heart disease. To this aim, 29 untreated patients with borderline-to-moderate essential hypertension underwent an echo-Doppler evaluation to determine left ventricular thickness and mass. From transmitral flow, the ratio between late and early filling velocities (A/E ratio) was used to assess left ventricular diastolic behaviour. On the same day that ultrasonic study was carried out, we also measured a set of casual blood pressures; conducted a mental arithmetic test (standardized series of mental subtractions); a handgrip test (30% of maximum voluntary contraction for 3 minutes); and performed noninvasive ambulatory monitoring of blood pressure (Spacelabs 5200). Significant relationships were observed between left ventricular mass and both night-time systolic blood pressure (r = 0.46, P less than 0.02) and peak systolic blood pressure during mental stress (r = 0.39, P less than 0.05). The A/E ratio was significantly associated with casual systolic and diastolic blood pressure (r = 0.45, P less than 0.02; r = 0.38, P less than 0.05, respectively); day-time diastolic blood pressure (r = 0.47, P less than 0.02); night-time systolic and diastolic blood pressure (r = 0.44, P less than 0.05; r = 0.42, P less than 0.05 respectively); and peak systolic blood pressure during the mental arithmetic test (r = 0.44, P less than 0.05). Our results seem to confirm the presence of a relationship between causal blood pressure and left ventricular filling. Moreover, the transmitral flow seems to be dependent on both mean levels of blood pressure on ambulatory monitoring and systolic blood pressure during mental stress. As concerns left ventricular mass, the correlations observed support the weakness of the links between blood pressure and left ventricular anatomy.

Comparison of ambulatory left ventricular ejection fraction and blood pressure in systemic hypertension in patients with and without increased left ventricular mass

To evaluate the effects of long-standing systemic hypertension on left ventricular (LV) function during daily activities, ambulatory radionuclide monitoring of LV ejection fraction (EF) and blood pressure was performed during exercise and other structured activities in 31 hypertensive patients. Patients were divided into 3 groups based on the absence of LV hypertrophy (group 1 [n = 16], LV mass 107 +/- 12 g/m2), presence of LV hypertrophy without electrocardiographic changes (group 2 [n = 10], LV mass 141 +/- 8 g/m2) and LV hypertrophy with associated electrocardiographic changes (group 3 [n = 5], LV mass 158 +/- 9 g/m2). The groups were similar with respect to age, baseline medication, treated and untreated blood pressure, resting EF and treadmill exercise time. Patients in group 3 had the longest history of hypertension. Peak filling rate was normal in group 1 (2.9 +/- 0.4 end-diastolic volume/s), but reduced at rest in groups 2 (2.4 +/- 0.4) and 3 (2.1 +/- 0.3). Patients in group 1 had normal EF responses to exercise and mental stress testing, as well as during routine ambulatory activities. Patients in group 2 had a blunted EF response to exercise, and those in group 3 had a significantly abnormal response. Both group 2 and 3 patients demonstrated abnormal EF responses to mental stress, as well as cold pressor testing in association with significant increases in mean arterial pressure and marked reduction in diastolic filling rate. Decreases in EF were also observed during routine patient monitoring in 3 group 3 patients and 4 group 2 patients. These events were associated with significantly increased blood pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

Left ventricular systolic response to exercise in patients with systemic hypertension without left ventricular hypertrophy

Supine exercise radionuclide angiography was performed in 367 men to assess left ventricular (LV) systolic response to exercise; 58 had systemic hypertension without LV hypertrophy on a resting electrocardiogram and 309 were normotensive. All patients met the following criteria defining a low pretest likelihood of coronary artery disease: age less than 50 years; normal electrocardiographic response to exercise; absence of typical or atypical chest pain; and exercise heart rate greater than 120 beats/min. Patients taking beta-receptor blockers were excluded. There were no significant differences between hypertensive and normotensive groups in peak exercise heart rate, workload or exercise duration. However, hypertensive patients had significantly higher peak exercise systolic blood pressures and peak exercise rate-pressure products. There were no differences between patients with and without hypertension in resting ejection fraction, peak exercise ejection fraction (hypertensive patients 0.71 +/- 0.01, normotensive patients 0.70 +/- 0.05) or change in ejection fraction at peak exercise (hypertensive patients 0.07 +/- 0.01, normotensive patients 0.07 +/- 0.04). Diastolic and systolic ventricular volumes tended to be smaller in the hypertensive patients, but the difference was not statistically significant. The change in systolic volume with exercise was similar in the 2 groups (hypertensive -10 +/- 3 ml/m2, normotensive -10 +/- 1 ml/m2). In the absence of electrocardiographic evidence of LV hypertrophy, systemic hypertension does not influence LV systolic response to exercise.

Impaired left ventricular functional reserve in hypertensive patients with left ventricular hypertrophy

To determine whether patients with hypertension and especially those with left ventricular hypertrophy have subtle changes in cardiac function, we measured the increase in left ventricular ejection fraction and in systolic blood pressure to end-systolic volume index ratio with exercise in 40 hypertensive patients and 16 age-matched normotensive volunteers. Twenty-two hypertensive patients without hypertrophy had normal end-systolic wall stress at rest and exercise responses. In contrast, the 18 patients with echocardiographic criteria for left ventricular hypertrophy demonstrated a significant increase in end-systolic wall stress at rest compared with normal subjects (69 +/- 16 vs. 55 +/- 15 10(3) x dyne/cm2, p less than 0.05) despite having normal resting left ventricular size and ejection fraction. In patients with left ventricular hypertrophy, the increase in ejection fraction with exercise was less than in the normotensive control subjects (7 +/- 7 vs. 12 +/- 8 units, p less than 0.05), and delta systolic blood pressure to end-systolic volume with exercise was reduced (3.3 +/- 3.8 vs. 8.3 +/- 7.7 mm Hg/ml/m2, p less than 0.05). The hypertensive patients with hypertrophy displayed a shift downward and to the right in the relation between systolic blood pressure to end-systolic volume ratio and end-systolic wall stress compared with control subjects and hypertensive patients without left ventricular hypertrophy. Thus, hypertensive patients with left ventricular hypertrophy by echocardiography and normal resting ejection fraction exhibit abnormal ventricular functional responses to exercise. This finding may have implications in identifying patients at higher risk for developing heart failure.

Hemodynamic effects of dilevalol in patients with systemic hypertension and left ventricular dysfunction

Hemodynamic and left ventricular function parameters were measured in patients with mild to moderate hypertension and compromised left ventricular function who were given dilevalol, an antihypertensive agent with selective beta 2-agonism and nonselective beta-antagonist activity. After a 2- to 3-week placebo washout period, 9 patients were given dilevalol titrated upward from 100 to 600 mg twice daily over a 7-week period to achieve a supine diastolic blood pressure of less than 90 mm Hg with a decrease of greater than or equal to 10 mm Hg from baseline. Multigated radionuclide ventriculography and systolic and diastolic time intervals were performed after the pretreatment placebo washout, at the end of 2 weeks' maintenance dosing, and after a 7- to 10-day post-treatment discontinuation and placebo washout period. At an average daily dose of dilevalol, 444 mg, heart rate at rest decreased significantly (p less than 0.01) during treatment and increased during post-treatment placebo. Systolic and diastolic blood pressures at rest decreased significantly (p less than 0.01) during treatment and increased during post-treatment placebo. At maximal exercise, changes in blood pressure and heart rate were significantly blunted (p less than 0.05) during treatment. Ejection fraction at rest increased significantly (p less than 0.01) during treatment, with no significant change occurring during exercise, and decreased during post-treatment placebo. Preejection period decreased significantly during treatment (p less than 0.005) and increased during post-treatment placebo.(ABSTRACT TRUNCATED AT 250 WORDS)

Mechanism of prolongation of pre-ejection period in the hypertrophied left ventricle with normal systolic function in unanesthetized hypertensive dogs

To determine the mechanism for prolongation of pre-ejection period (PEP) in the hypertensive heart with normal systolic function, cardiac catheterizations, echocardiograms, and electrocardiograms were performed at the baseline period (CS, control stage) and eight weeks (HS, hypertensive stage) after the induction of systemic hypertension by Page's method in unanesthetized dogs. Mean aortic blood pressure increased significantly (96 +/- 12 to 137 +/- 26 mmHg) (p less than 0.05). Diastolic aortic pressure also increased significantly (80 +/- 12 to 118 +/- 24 mmHg) (p less than 0.01). Left ventricular (LV) PEP of HS was significantly prolonged (72 +/- 12 vs. 87 +/- 22 ms, CS vs. HS). The ratio of LV pre-ejection period to ejection time (PEP/ET) also increased significantly (0.33 +/- 0.04 to 0.42 +/- 0.07) (p less than 0.05). LV end-diastolic wall stress as an index of preload decreased significantly (7.7 +/- 2.5 vs. 5.9 +/- 1.8 10(3) dynes/cm2, CS vs. HS). Heart rate, mean velocity of circumferential fiber shortening (VCF) and end-systolic wall stress of HS did not change. That is, myocardial contractility in the hypertensive heart of HS most likely is not depressed. At autopsy, left ventricle to body weight ratio of HS was significantly (p less than 0.01) greater than the sham-operated dogs (5.7 +/- 0.8 vs. 4.3 +/- 0.5 g/kg). From these findings, there are two possible factors responsible for prolongation of PEP of HS. First, elevated diastolic aortic pressure may influence PEP. Second, the prolonged PEP is possibly caused by the decrease of preload.(ABSTRACT TRUNCATED AT 250 WORDS)

Diltiazem and left ventricular hypertrophy in renovascular hypertensive rats

The effects of diltiazem treatment (40-50 mg/kg/day orally for 8 weeks) of left ventricular hypertrophy on systemic and coronary hemodynamics and mechanical cardiac performance were investigated in renovascular hypertensive rats (Goldblatt, two-kidney, one clip). Systemic and coronary hemodynamics were determined by using radioactive microspheres in conscious, unrestrained rats. Mechanical performance was measured on isolated papillary muscle from the same animal. Nine treated hypertensive rats were compared with control groups: 12 untreated hypertensive and nine sham-operated rats. Diltiazem treatment led to an effective but incomplete control of blood pressure (from 208 +/- 5 mm Hg in the untreated hypertensive group to 155 +/- 3 mm Hg in the treated hypertensive group; p less than 0.01) associated with a significant but incomplete decrease of the left ventricular mass (from 3.10 +/- 0.19 mg/g in untreated hypertensive rats to 2.35 +/- 0.04 mg/g in treated hypertensive rats; p less than 0.01). A close correlation was found between left ventricular mass and systolic blood pressure in untreated, treated, and pooled groups (r = 0.84, p less than 0.001, n = 30). The left ventricular weight to systolic blood pressure ratio was equivalent in all three groups, so that the reduction of left ventricular mass in diltiazem-treated rats was commensurate with the reduction of blood pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

Exaggerated systolic blood pressure response to exercise: a normal variant or a hyperdynamic phase of essential hypertension?

This study examines the left ventricular function (by first-pass radionuclide angiography with a multicrystal gamma camera) at rest and during symptom-limited upright exercise in 27 normal subjects (group 1), 25 normotensive subjects with exaggerated systolic blood pressure response to exercise (greater than 200 mm Hg) (group 2) and 25 patients with essential hypertension and no associated coronary artery disease (group 3). There were no significant differences between groups 1 and 2 in exercise tolerance, heart rate, total vascular resistance, left ventricular ejection fraction and end-systolic volume. However, the exercise cardiac index and systolic blood pressure were significantly higher in group 2 (P less than 0.02). Compared to group 3, the subjects in group 2 had higher exercise heart rate (P less than 0.0001), cardiac index (P less than 0.0001), systolic blood pressure (P less than 0.0001) and left ventricular ejection fraction (P less than 0.0001) and lower exercise total vascular resistance (P less than 0.0002) and end-systolic volume (P less than 0.01). Thus, the hemodynamic profile in subjects with exaggerated systolic blood pressure response to exercise differs from that of essential hypertension; it may represent a supernormal response.