Noninvasive evaluation of coronary velocity reserve: need for correction of the sympathetic tone

Introduction

Noninvasively Doppler estimated coronary velocity (as a surrogate of flow) reserve (CVR) by adenosine is a useful parameter for risk stratification in chronic coronary syndromes (CAD). However, baseline velocity fluctuation due to sympathetic drive, as in mental stress, may affect the evaluation of the actual CVR.

Aim

Aim of the study was to assess the effect of b blocker administration following adenosine infusion in the coronary velocity and thus the consequences in the estimated CVR.

Patients and methods

Sixty (females 8) patients (pts) with stable CAD (mean/SD: age 64/10, ejection fraction % 55/8) were studied before the performance of a dobutamine stress echo. Distal left anterior descending (LAD) velocity was estimated at rest (CVrest), at maximal adenosine infusion (140γ/kg/min: CVaden) and following esmolol infusion 3–5 min later (CVbbl). CVR was estimated using as baseline velocity either CVrest (CVRrest) or CVbbl (CVRbbl). Respective changes of heart rate (HR) and systolic blood pressure (SBP) were also estimated.

Results

CVbbl was smaller than CVrest (23/7 vs 29/13, p<0.0.01). Thus, CVRbbl was greater than CVRrest (3/0.9 vs 2.7/0.6, p<0.001) with an absolute difference (dCVR) of 0.46/0.84, a % difference (%dCVR) of 23/34%, with a modest linear relationship (R2=0.08, p=0.02 figure). The %dCVR was also linearly related to CVRrest (R2=0.13, p=0.003 figure) and it was independent from age, HR/BP changes and the dobutamine stress echo outcome.

Differences between CVRbbl and CVRrest were greater in females (females/males: dCVR 1.2/0.9 vs 0.36/0.8, %dCVR 0.67/0.56 vs 0.36/0.26, both p<0.001).

Conclusions

Noninvasively estimated CVR is affected by the baseline sympathetic tone, irrespectively from the age in stable CAD. A gender effect is evident, reiterating the microvascular susceptibility in females. Thus, potential mental stress background must be considered, and b-blockade subsequently might be applied during CVR evaluation to overcome any sympathetic effect.

Funding Acknowledgement

Type of funding sources: None.

Dynamic changes of left atrial function during supine ergometry: evidence for interplay with left ventricular function and dynamic changes of pulmonary pressure

Introduction

Despite the pivotal role of left atrial (LA) function in a variety of cardiac pathologies, it has been studied mainly at rest.

Aim

Aim of the study was to assess the effect of semisupine exercise ergometry (Ex) on LA function, by volumetric and strain parameters and to interrogate relationships with left ventricular (LV) function and noninvasive hemodynamics.

Patients and methods

Eighty-two patients (female 26, age: mean/SD 61/15) referred for Ex were studied. The following parameters were estimated by 2 D echo: LV systolic (LVvolsyst) and diastolic (LVvoldiast) volume, ejection fraction (LVEF), stroke volume (LVsv), LA minimum (LAvolmin) and maximal volume (LAvolmax), LA emptying fraction [LAEF), LA reservoir volume (LAvolres = LAvolmax − LAvolmin), LA reservoir fraction (LAresFR = LAvolres/LVsv), LA conduit volume (LAcondvol = LVsv − LAvolres) and LA conduit fraction (LAcondFR = LAcondvol/LVsv). LV strain (LVSR) and LA strain (LASR) were estimated by 2D analysis. Peak tricuspid gradient (TRpg) was also estimated. Parameters were measured at rest R and Ex and the respective % changes (%d) were calculated.

Results

SBE performance was efficient with a % achieved target heart rate 73/9 and workload Watts 96/21. Systolic blood pressure increased from 139/53 to 179/31. Parameters with significant change during Ex are in the table (all p<0.001).

LVSRr and LVEFr were both related inversely with LAvolresR (r=−0.39/p=0.001 and r=−0.24/p=0.05) and LAresFRr (r=−0.34/p=0.001 and r=−0.25/p=0.04). LVEFr was related inversely with LAcondRFr r=−0.24/p=0.04). LVSR was related inversely with LAvolresEx (r=−0.43/p=0.001). LVSREx was related inversely with LAvolresR (r=−0.24/p=0.04) and LAcondRFr (r=−0.25/p=0.04).

The %dLVSR was related inversely with LAEFr (r=−0.25/p=0.04). The %dLVEF was related inversely with LAresFREx (r=−0.27/p=0.03) and LAcondRFr (r=−0.27/p=0.03).

The % increase in TRpg during SBE was positively related with LAresFREx r=0.30/p=0.04 and inversely with LAcondFREx (r=−0.30/p=0.04) (Figure 1).

Conclusion

SBE induces LA dynamic changes in a spectrum of volumetric and strain indices. Dynamic changes of LV are related with reservoir and conduit LA function. LA reservoir and conduit function during SBE are related with the induced dynamic changes of pulmonary pressure, thus further supporting the clinical relevance of the respective evaluation.

Funding Acknowledgement

Type of funding sources: None.

Meta-analysis for cardiovascular risk stratification based on noninvasive left anterior descending velocity reserve

Introduction

Left anterior descending velocity reserve (LADVR) by transthoracic echocardiography (TTE) has been proposed for cardiovascular risk stratification in observational prospective studies. Aim of the current study was to interrogate the prognostic consistency and coherence of the existing LADVR data by the means of meta-analysis of relevant studies.

Methods

A systematic research through electronic databases was performed for prospective studies with patients with known or suspected coronary artery disease (CAD) who had LADVR data.

The exposure was abnormal values of LADVR as defined in each study and the outcome was the occurrence of cardiovascular event or death (CE-D). Statistical index considered were the risk ratio (RR) for CE-D of patients with abnormal vs. normal LADVR, as obtained from Cox proportional hazard models.

A meta-analysis of these studies using random-effects model was performed to evaluate the pooled prognostic value of abnormal LADVR.

Results

Fifteen studies with 13050 patients (59.7% male; mean age 64.2 years; mean follow-up 25.1 months) were included in this meta-analysis. Every study used adjustments for every established risk factor for CE-D (age, hypertension, diabetes, dyslipidemia, smoking habits, wall motion abnormalities during stress echo). The abnormal value of LADVR was associated with an increased risk of CE-D (RR=3.33, 95% CI: 2.54–4.37, p-value <0.001). Moderate heterogeneity was observed between studies (Q=35.83, p-value=0.001, I2=60.9%) which was further investigated with sensitivity analysis, subgroup analysis and meta-regression.

Conclusions

Meta-analytic data for the cardiovascular risk stratification based on dichotomous LADVR data provide robust evidence for efficient prognostic yield.

The current results support the broader clinical application of the LADVR.

LADVR meta-analysis forestplot

Funding Acknowledgement

Type of funding source: None

P763 Asymptomatic severe organic mitral regurgitation: Does the anatomic substrate affect the functional response to supine ergometry?

Methods

32 patients with Deg (male M/female F = 15/17) and 19 with MyxS (M/F = 7/12) were studied at rest (R) and Ex.

We estimated

heart rate (HR), rate-pressure product (HRxBP), LV endsystolic (LVESV)- enddiastolic volume (LVEDV), ejection fraction (EF), LV longitudinal strain (GLS), transmitral E wave (E), ratio E/e, peak tricuspid gradient (TrPG). To adjust for a potential volume effect on GLS, GLS was normalized to volumes and respective ratios were considered (GLS/LVESV, GLS/LVEDV). Parameters were measured at R and Ex and % changes were calculated : %d (Ex-R).

Results

Myx and Deg had similar chronotropic reserve and HR-BP. Myx were younger, and during Ex they had a greater LVEDV, a greater EF. a smaller E/e, and a smaller TrPG compared with Deg.

Myx group, despite having a better GLS both at R and Ex, revealed a smaller % GLS improvement from R to Ex (15% vs 32%). The normalized GLS/LVESV and GLS/LVEDV were similar at R between Myx and Deg, but they showed a smaller improvement during Ex in Myx. (table-results)

Conclusion

Despite similar severity of MR, asymptomatic patients with MyxS revealed a different dynamic profile during Ex compared with Deg. The underlying MV substrate in organic MR might be related with a different LV adaptation to volume loading combined with subsequent uneven stress induced hemodynamic response.

The disparities found might have implications both in the nature history of MR as well as in the decision making for intervention.

RESULTS Parameter DegS MyxS p Age(years) 65 ± 11 44 ± 12 <0. 001 LVEDV Ex (ml) 85 + 32 117 ± 41 =0. 007 EF Ex(%) 65 + 7 69 ± 8 =0. 05 GLS R(%) -17.6 ± 6.8 -22.2 ± 4.3 =0. 04 GLS Ex(%) -22 ± 4 -25.0 ± 5.7 =0. 05 % d (Ex-R) LV strain/endsystolic volume 0.84 ± 0.4 -0.54 ± 0.5 =0. 05 E/e" Ex 16.7 ± 8.8 9.7 ± 2.2 =0. 004 TrPG Ex(mmHg) 59 ± 11 44 ± 11 =0. 0001

P1382 Evidence for longitudinal aorta strain relationship with noninvasive left ventricular myocardial work: another component for the ventricular-aorta coupling?

Methods

Fifty four normals, 24 males (M) and 30 females(F), age: 52 ± 13 (25-75 years), were selectively studied, provided that they had an efficient image quality to apply both AFI analysis for MW estimation and ascending aorta interrogation for AoLSTR (EchoPac GE) .

LAoLSTR was measured in the posterior aorta wall (apical long axis view). Aortic wall borders were traced longitudinally adjusting width using 4 points of interest. The first point was put at the sinotubular junction and approximately 3-4 cm of the ascending aorta were analyzed. 2D-SpTa divided the regions of interest into proximal, middle and distal segments and the respective peak LAoSTR were considered.

The following indexes of MW were estimated: GWI (global work index = total work from mitral valve closure to mitral valve opening), GCW (global constructive work = total work contributing to pump function, namely due to shortening during isovolumic contraction and ejection and lengthening during isovolumic relaxation), GWW (global wasted work = elongation during isovolumic contraction/ejection and shortening during isovolumic relaxation), GWE (global work efficiency = fraction of GCW/[GCW + GWW]).

AFI derived LV strain (LVGS), biplane LV ejection fraction and stroke volume (SV) were also calculated.

Results

LAoSTR in any wall position was not affected by age. LAoLSTR of the proximal segment was related to both EF and LVGS (r = 0.31, p = 0.03 and r=-0.28 p = 0.05, respectively). Middle and distal LAoSTR were not related to either EF or LVGS. SV was not related to any of LAoSTR.

LAoSTR of the proximal segment was related to both GWI and GCW ( r = 0.34 p = 0.016 and r = 0,31 p = 0.03 respectively).

LAoSTR of the middle and distal segments were not related with any LV MW parameters.

Conclusion

Longitudinal aorta strain evaluation by 2D-SpTa is feasible and it is related with functional performance of the LV estimated by either conventional or MW indices based on 2D-SpTa. Moreover , the longitudinal performance of the proximal segment of the aorta above the sinotubular junction is linked to the constructive component of the LV myocardial work thus providing an alternative evidence for the LV ventricular–aorta coupling which was independent from aging.

Thyroid hormone is a critical determinant of myocardial performance in patients with heart failure: potential therapeutic implications

OBJECTIVE

Previous experimental studies have provided evidence showing that changes in thyroid hormone signaling correspond to alterations in myocardial function in animal models of heart failure. The present study further explores whether thyroid hormone alterations are correlated with the functional status of the myocardium in patients with heart failure.

METHODS

In this study, 37 patients with mean ejection fraction (EF%) of 26.2 (8.2) were included. Myocardial performance was assessed by echocardiography and cardiopulmonary exercise testing. Total tri-iodothyronine (T3), thyroxine, and TSH levels were measured in plasma.

RESULTS

Total T3 was strongly correlated with VO2max (r = 0.78, P = 2 x 10(-8)). Furthermore, multivariate analysis revealed that total T3 was an independent predictor of VO2max (P = 0.000 005). A weaker but significant correlation was also found between total T3 and EF% (r = 0.56, P = 0.0004), systolic (r = 0.43, P = 0.009) and diastolic (r = 0.46, P = 0.004) blood pressure.

CONCLUSIONS

changes in thyroid hormone were closely correlated to myocardial functional status in patients with heart failure. These data probably indicate a possible role of thyroid hormone in the pathophysiology of heart failure and confirm previous experimental reports.

[Prognostic value of ventricular longitudinal systolic velocities and maximal oxygen consumption in patients with dilated cardiomyopathy]

OBJECTIVE

To compare the prognostic value of regional longitudinal ventricular systolic velocities with that of maximal oxygen consumption (VO(2max)) in patients with dilated cardiomyopathy (DCM).

METHODS

VO(2max) derived from cardiopulmonary exercise tests and regional longitudinal ventricular systolic velocities obtained from tissue Doppler imaging were compared in 18 DCM patients with cardiac events (death, cardiac transplantation, hospitalization, group A) and 24 patients without cardiac events (group B). Peak velocities during isovolumic contraction (is) and ejection (ez) were interrogated at the mitral or tricuspid annulus (site 1), at the mid parts of the walls (site 3, at the level of papillary muscle), and at the midpoints (site 2) between sites 1 and 3 of interventricular septum (S), lateral wall of LV (L) and of RV (R) in apical 4 chambers view.

RESULTS

R1is, R2is, R2ez, R3is, S1is, S1ez, S2ez, L1is, L1ez and L2ez of group A were significantly lower than those in group B (all P < 0.05). Independent of VO(2max), high sensitivity and specificity were shown for R3ez, S1ez, L1ez, L1is, L2is and L3is in predicting cardiac events of DCM patients.

CONCLUSION

LV and RV systolic velocities could independently predict cardiac events in DCM patients.

Pre-treatment with Irbesartan attenuates left atrial stunning after electrical cardioversion of atrial fibrillation

AIMS

Left atrial (LA) stunning, the transient impairment of LA function, is responsible for an increased thrombo-embolic risk after cardioversion of atrial fibrillation (AF). Angiotensin receptor blockers (ARBs) attenuate atrial remodelling in AF and could theoretically influence LA stunning. We studied the effect of Irbesartan on LA stunning.

METHODS AND RESULTS

We prospectively assigned 50 patients from the outpatient clinic undergoing electrical cardioversion for AF with duration of >4 weeks, into two matched groups: 25 patients were treated with Irbesartan (228+/-93 mg/day) for at least 2 weeks prior to cardioversion (Irbesartan group); 25 patients did not receive ARBs (control group). The groups did not differ concerning age (64+/-13 vs. 63+/-13 years, respectively), AF duration (20+/-18 vs. 20+/-19 weeks), underlying disease, LA diameter (46+/-7 vs. 47+/-9 mm), left ventricular dimensions, and ejection fraction (47.7+/-11.6 vs. 49.7+/-14.5%). We assessed LA appendage emptying velocities (LAAEV) and LA spontaneous echo contrast (LASEC) by transoesophageal echocardiography before and after cardioversion and at 2 weeks, and the A-wave by transthoracic echocardiography after cardioversion, at 2 and at 4 weeks. LA stunning was significantly attenuated in the Irbesartan group. The reduction of LAAEV immediately after cardioversion was significantly less in the Irbesartan group (LAAEV reduction of 9+/-49% from 28+/-9 cm/s before cardioversion to 25+/-13 cm/s immediately afterwards) than in the control group (reduction of 48+/-20% from 34+/-15 cm/s before cardioversion to 16+/-6 cm/s afterwards) (P = 0.048). New or increased LASEC occurred in eight patients (32%) in the Irbesartan vs. 16 patients (64%) in the control group (P = 0.046).

CONCLUSION

Irbesartan significantly attenuates LA stunning after electrical cardioversion of AF. Therefore, ARBs may represent an important pharmacological supplementation in patients being prepared for cardioversion.

Prediction of restenosis after coronary angioplasty by use of a new index: TIMI frame count/minimal luminal diameter ratio

BACKGROUND

It has been shown recently that postangioplasty coronary flow reserve and the degree of residual stenosis have a modest predictive value for short- and long-term clinical outcomes after coronary angioplasty. Corrected TIMI frame count (CTFC) is a simple quantitative index of coronary blood flow. Its relationship with Doppler coronary flow velocity and clinical outcome after coronary angioplasty has not been fully clarified. The aim of this study was to identify clinical, angiographic, and functional predictors of clinical and angiographic restenosis after conventional coronary angioplasty.

METHODS AND RESULTS

We studied 70 consecutive patients in whom intracoronary Doppler flow-velocity measurements were performed before and after angioplasty. Patients were evaluated for restenosis by clinical follow-up, exercise stress test/(201)Tl scintigraphy, and follow-up angiography, which was performed at 10. 5+/-10.3 months in 63 patients. According to the results of univariate analysis, a new index, postangioplasty CTFC/minimal luminal diameter (MLD) ratio, was created. Multivariate analysis revealed that CTFC/MLD ratio was the only independent predictor of angiographic (OR 2.02; 95% CI 1.37 to 2.97; P<0.0004) and clinical (OR 1.60; 95% CI 1.15 to 2.21; P<0.005) restenosis. The receiver operating characteristic curve area of this index was 79% for angiographic and 73% for clinical restenosis. The optimal CTFC/MLD ratio cutoff values were 7.88 for angiographic and 7.94 for clinical restenosis, respectively.

CONCLUSIONS

Our data indicate that postangioplasty CTFC/MLD ratio, which incorporates both the angiographic and functional features of coronary lesions, is a reliable, objective, and inexpensive index for prediction of angiographic and clinical restenosis after conventional coronary angioplasty.

Dispersion of ventricular repolarization is determined by the presence of myocardial viability in patients with old myocardial infarction. A dobutamine stress echocardiography study

AIMS

The study sought to investigate the relationship of myocardial viability detected by dobutamine stress echocardiography to changes of QT dispersion and to the presence of arrhythmias during dobutamine infusion in patients with old myocardial infarction. We also examined whether patency of the infarct-related artery is associated with the presence of myocardial viability and QT dispersion.

BACKGROUND

QT dispersion and myocardial variability have been associated with the presence of arrhythmias during late post infarction but not during dobutamine stress. Restoration of anterograde coronary flow has beneficial effects on ventricular systolic function and repolarization, suggesting that the extent of viable myocardium may determine ventricular repolarization.

METHODS

Seventy five patients with previous myocardial infarction were studied in a low dose (up to 20 microg(-1) x kg(-1) x min(-1)) dobutamine stress echocardiography study. ECGs were obtained at rest and peak stress for measurement of QT intervals. The presence of ventricular arrhythmias (Lown grade >lb) during stress was noted. A reduction in the total wall motion score of the left ventricle at peak stress confirmed the presence of myocardial viability.

RESULTS

Dobutamine infusion increased QT dispersion in all patients (P<0.01). Patients with myocardial viability had a lower resting QT dispersion (P<0.05) and a greater increase in QT dispersion% (P<0.01) than patients without. The combination of a resting QT dispersion <65 ms or an increase in QT dispersion >30% predicted viability with a sensitivity of 67%, a specificity of 96%, and an accuracy of 78%. A patent infarct-related artery, as well as ventricular arrhythmias, were more commonly observed in patients with evidence of viable myocardium (P<0.05). Patients with arrhythmias had a higher QT dispersion than patients without (P<0.05).

CONCLUSION

The combination of a resting QT dispersion +/-65 ms or an increase in QT dispersion >30% predicts the presence of viable myocardium and thus, may represent a simple index for the assessment of viability in everyday clinical practice. Myocardial viability is related to a patent coronary artery and to a high incidence of arrhythmias accompanied by a greater increase in QT dispersion at peak dobutamine infusion.

Usefulness of flow reserve in the left internal mammary artery to determine graft patency to the left anterior descending coronary artery

Two-dimensional Doppler echocardiography (DE) and intravascular Doppler-tipped guidewire (flowire) have been used to measure flow in aortocoronary conduits at rest and during hyperemia, but they have not been compared. We investigated which flow velocity parameters obtained with these 2 different techniques can predict left internal mammary artery (LIMA) graft patency. Twenty-nine patients with previous coronary artery bypass grafting referred for evaluation of symptoms of coronary artery disease were studied after cardiac catheterization using the flowire and DE. Proximal LIMA graft flow velocity was measured at rest and during hyperemia produced by 140 microg/kg/min of intravenous adenosine infusion over 6 minutes with both methods. Normal LIMA grafts and left anterior descending artery (LAD) distal to the anastomosis were present in 16 patients, whereas 13 had >70% graft or native vessel stenosis. The coronary flow velocity reserve (r = 0.79) and the diastolic-to-systolic velocity ratio during hyperemia (r = 0.73) correlated very well between the 2 techniques. Among the variables obtained with the 2 techniques, the intragraft coronary flow velocity reserve measured by both methods was the only independent predictor of graft/recipient LAD patency. This variable had a sensitivity and specificity of 86% at a cutoff point of 2.07 with the flowire method and 83% at a cutoff point of 1.54 with DE. The areas below the receiver-operating characteristic curves were 0.91 and 0.93, respectively. Coronary flow velocity reserve measurements obtained with DE appears a reliable noninvasive method for assessing LIMA graft and/or LAD distal to the anastomosis patency in patients after bypass surgery and correlate very well with those directly obtained by intravascular Doppler.

Double-inlet and double-outlet left ventricle in situs inversus

Double-outlet left ventricle is a rare congenital cardiac malformation that has been traditionally difficult to diagnose accurately. We report a unique case of situs inversus totalis, L-loop, double-inlet left ventricle and double-outlet left ventricle with pulmonary stenosis, diagnosed mainly by transesophageal echocardiography and magnetic resonance imaging.

Effect of plaque burden on coronary vasoreactivity in early atherosclerosis

Coronary atherosclerosis, during its initial stages of development, may result in abnormal endothelium-dependent vasomotor responses. The relation between the degree of vasoreactivity and the amount of atheromatous plaque load has not been decisively determined. The aim of the present study was to investigate the effects of segmental plaque burden on endothelium-dependent and independent coronary stimulation. We studied 37 individual coronary segments along the course of coronary arteries that had angiographically either nonvisible or nonobstructive atheromatous lesions. Endothelium-dependent and independent stimulation of each segment from 10 patients with known significant coronary artery disease was examined with intracoronary administrations of normal saline, acetylcholine 10(-6) M and 10(-5) M, and nitroglycerin, respectively, using quantitative coronary angiography. Simultaneous vasomotor effects on the microcirculation were evaluated by a Doppler guidewire (Flowire). Subsequently, intracoronary ultrasound was used at each segment for detailed morphometric and composition analysis. By quantitative coronary angiography, when compared with normal saline, acetylcholine produced a reduction in minimal lumen diameter of 15.2 +/- 25.6%, and nitroglycerin produced an increase of 18.0 +/- 22.5%. The degree of vasoconstriction induced by acetylcholine correlated inversely (r = 0.51, p = 0.001) to the amount of segmental maximal plaque thickness. No relation between the response to nitroglycerin and the parameters obtained by intracoronary ultrasound was documented. Fibrous coronary plaques showed less vasomotor changes than plaques with mixed echogenicity, probably due to a significantly larger plaque burden. Acetylcholine produced overall a differential vasomotor response in the epicardial segments (vasoconstriction) compared with the microcirculation (vasodilation). These results indicate that in early atheromatous coronary lesions, the degree of endothelium-dependent vasoconstrictive response is inversely related to the amount of segmental plaque burden.

Magnitude of myocardial dysfunction is greater in painful than in painless myocardial ischemia: an exercise echocardiographic study

OBJECTIVES

This study sought to assess the presence and extent of inducible myocardial dysfunction during painful and painless (silent) myocardial ischemia in a homogeneous patient cohort with coronary artery disease and no previous myocardial infarction.

BACKGROUND

The functional significance of painless versus painful demand-driven ischemia remains controversial, with conflicting results in published reports regarding the amount of myocardium in jeopardy.

METHODS

Exercise echocardiography was performed in 89 patients (mean [+/- SD] age 59.3 +/- 8.2 years) with significant coronary artery disease and positive exercise stress test results. Patients were taking no antianginal medications and were classified into painless and painful cohorts after the outcome of a symptom-limited treadmill exercise test. No patients had previous coronary artery bypass surgery. Images were acquired in digital format before and immediately after treadmill exercise testing.

RESULTS

Fifty-eight patients had painful and 31 painless myocardial ischemia. Clinical and demographic characteristics as well as coronary artery anatomy were similar in both groups. Patients with painless ischemia achieved better exercise performance with greater exercise duration (p < 0.001) and higher maximal rate-blood pressure product (p < 0.001) than those with painful ischemia. New wall motion abnormalities were seen in 54 patients (93%) with painful versus 17 (55%) with painless ischemia (p < 0.001). Total ischemic score was greater in patients with painful than in those with painless ischemia (15.9 +/- 3.7 vs. 12 +/- 1.4, p < 0.001, respectively), with a greater number of ischemic myocardial segments in painful than in painless ischemia (101 [16%] vs. 21 [6%], p < 0.001, respectively).

CONCLUSIONS

Patients with painless ischemia frequently have regional myocardial dysfunction on exertion detected by echocardiography, but painful episodes are accompanied by a greater magnitude of myocardial dysfunction.

Echocardiographic measures of left ventricular structure and their relation with rest and ambulatory blood pressure in blacks and whites in the United Kingdom

OBJECTIVES

This study attempted to determine whether people of black African descent have more left ventricular hypertrophy than those of white European descent and whether this can be explained by rest or ambulatory blood pressure.

BACKGROUND

Mortality associated with hypertension is higher in black populations than among whites, but differences in morbidity and their associations with blood pressure are inconsistent.

METHODS

We examined 1,166 black and white men and women 40 to 64 years old in a community survey in London, United Kingdom. Echocardiograms were obtained for all subjects and ambulatory blood pressure recordings for 319.

RESULTS

Adjusted for body size, ventricular septal thickness was greater in blacks than whites (p < 0.05), and cavity dimension was smaller (p < 0.05). In men, ventricular septal thickness was > 10 mm for 32% of whites and 53% of blacks; for women these figures were 14% and 38%, respectively. Relative wall thickness was greater in blacks (p < 0.01 for men and women), but left ventricular mass index was similar in the two ethnic groups. In men, hypertension resulted in an increase in wall thickness in both ethnic groups, but cavity dimension decreased in blacks and increased in whites. Wall thickness was higher in blacks than in whites for equivalent levels of either rest (p = 0.05) or ambulatory (p = 0.007) blood pressure.

CONCLUSIONS

Left ventricular mass index may not be valid for comparison between ethnic groups because this derived measure does not take into account ethnic differences in ventricular structural response to hypertension. Interventricular wall thickness may be more valid. Using this measure, we demonstrate greater ventricular hypertrophy in blacks than in whites, unexplained by differences in either rest or ambulatory blood pressure. The pattern of ventricular hypertrophy observed in blacks is associated with an increased mortality risk. Conventional blood pressure thresholds for instituting antihypertensive treatment may be too conservative for people of black African descent.

Differential response of high-density lipoproteins to first-step lipid-lowering diet according to their initial level

BACKGROUND

A lipid-lowering diet has been shown to lower total cholesterol but also high-density-lipoprotein (HDL) cholesterol. The effect of the first-step lipid-lowering diet (as suggested by the European Atherosclerosis Society) on HDL levels was studied in 129 Greek patients aged 52.7 +/- 9.8 years, of whom 78 were men and 51 women of similar ages.

METHODS

Total, HDL, and low-density-lipoprotein (LDL) cholesterol, and the total: HDL cholesterol and triglyceride ratio were assessed before and 3 months after the diet.

RESULTS

Overall, total cholesterol decreased by 12% (P < 0.001), LDL by 15% (P < 0.001), HDL by 3% (NS), triglycerides by 12% (P < 0.01), and total: HDL cholesterol ratio by 11% (P < 0.001). A difference was found in the response to diet according to baseline HDL levels: in patients with HDL of 39 mg/dl or higher (group A), HDL decreased by 10% and the total: HDL cholesterol ratio by 3%, whereas in those with HDL lower than 39 mg/dl (group B) HDL increased by 17% and the total: HDL cholesterol ratio decreased by 22%. The difference between the groups was statistically significant (P < 0.001) for these two values as well as for triglycerides, but not for total cholesterol and LDL. No difference in the responses between men and women was found.

CONCLUSION

This differential response to diet should be taken into account when planning treatment. Patients with baseline HDL levels higher than 39 mg/dl should probably be considered for early treatment not only by diet but by lipid-lowering-HDL-raising drugs as well.

Beat-to-beat variability in stroke volume during VVI pacing as predictor of hemodynamic benefit from DDD pacing

To determine whether the magnitude of Beat-to-Beat variability in stroke volume (SV) during VVI pacing can predict hemodynamic benefit from DDD pacing, we undertook Doppler recordings of systolic and diastolic LV flow during VVI and DDD pacing in 20 patients (age 54 +/- 9 years) with DDD pacemakers implanted due to AV block. SV increased by 19% +/- 10% from VVI to DDD (P < 0.01). This increase was greater (29% +/- 9%) in patients with a ratio of early (E)/late (A) filling < 1 compared to those with E/A > 1 (10% +/- 9%) (P < 0.001). Beat-to-Beat variability in SV was greater in VVI (13% +/- 8%) compared to DDD (4% +/- 1%) (P < 0.001). Patients with E/A < 1 showed greater Beat-to-Beat variability in SV during VVI pacing (19 +/- 6%) compared to those with E/A > 1 (8% +/- 4%) (P < 0.001). Beat-to-Beat variability in SV during VVI pacing correlated with both percent change in SV from VVI to DDD (r = 0.89, P < 0.001) and E/A (r = -0.71, P < 0.001). In conclusion, patients with E/A < 1 derive greater hemodynamic benefit at rest from DDD pacing compared with E/A > 1. In addition, patients with complete AV block who show large variations in SV during VVI pacing may obtain greater hemodynamic benefit at rest from DDD pacing than patients with small variations.

[Systemic lupus erythematosus: valvular regurgitation and its relation to anticardiolipin antibodies]

The aim of this study was to assess the relationship between the incidence and severity of valvular regurgitation and the presence of high levels of anticardiolipin antibodies in a group of patients with systemic lupus erythematosus. Fifty patients aged 35.5 +/- 13.4 years and 84 healthy age and sex matched controls were studied with two dimensional echocardiography with color flow imaging. IgG and IgM anticardiolipin antibodies were measured in all patients within a week of the echocardiographic study. Patients had a similar incidence of aortic, tricuspid and pulmonic regurgitation than normals. However there was a greater incidence of mitral regurgitation among patients (56 vs 21% p < 0.001). The seven patients with moderate or severe mitral regurgitation had Libman Sacks vegetations of the valve. Twenty five of 28 patients with mitral regurgitation had increased anticardiolipin antibodies; moreover, these levels were significantly higher among patients with mitral regurgitation and thickened mitral valves than those with normal valves. Patients with increased anticardiolipin antibodies had a higher incidence of Libman Sacks vegetations. No association between the presence of these antibodies and the severity of aortic, pulmonic or tricuspid regurgitation was observed. It is concluded that the incidence of mitral valve regurgitation is increased in systemic lupus erythematosus and related to raised anticardiolipin antibodies.

Doppler haemodynamic profiles of clinically and echocardiographically normal mitral and aortic valve prostheses

Doppler echocardiographic studies were performed in 380 consecutive patients with 415 normally functioning artificial valves to establish normal Doppler characteristics for each type of prostheses used in our institution, with particular reference to Starr-Edwards valves, and to serve as control studies for future assessment. None of the patients were in heart failure at the time of the study. Peak transaortic velocities (m.s-1) were higher and effective orifice areas (cm2) smaller in mechanical valves as a whole, when compared with bioprostheses (P less than 0.01); 2.7 +/- 0.7 and 1.4 +/- 0.55 for Starr-Edwards, 2.7 +/- 0.6 and 1.5 +/- 0.6 for Bjork-Shiley, 1.8 +/- 0.1 and 1.5 +/- 0.6 for Duromedics and 1.5 +/- 0.06 and 2 +/- 0.12 for bioprostheses, respectively. In the mitral position, the average peak diastolic velocities (m. s-1) and pressure half-times (ms) were higher in mechanical valves, but there was a large overlap between the various types and sizes of prostheses (P = NS); 1.6 +/- 0.3 and 98 +/- 25 for Starr-Edwards, 1.4 +/- 0.3 and 88 +/- 26 for Bjork-Shiley, 1.8 +/- 0.1 and 75 +/- 5 for Duromedics and 1.5 +/- 0.3 and 90 +/- 20 for bioprostheses, respectively. There was an inverse relation between valve size and pressure halftime for Starr-Edwards prostheses (P less than 0.01). Doppler flow characteristics in mechanical valves where similar in patients with normal and dysfunctioning prostheses. Valvular or myocardial dysfunction could best be ascertained when early postoperative studies were available for comparison.(ABSTRACT TRUNCATED AT 250 WORDS)