Effects of transluminal coronary angioplasty on left ventricular systolic and diastolic function at rest and during exercise

The left ventricular global and regional systolic function, ventricular volumes, and peak diastolic filling rate (PDFR) were studied in 30 patients with coronary artery disease, before and 2 to 5 days after transluminal coronary angioplasty (PTCA), utilizing equilibrium radionuclide angiography at rest and during exercise. At rest, the global ejection fraction (EF) was unchanged before (60 ± 9%) and after PTCA (62 ± 10%). During exercise, global EF increased from 59 ± 11% pre PTCA to 67 ± 10 post PTCA (p < 0.001). Twenty-two patients had abnormal EF response to exercise pre PTCA, versus seven post PTCA (p < 0.001). Improvements in exercise regional EF paralleled the changes in global EF. End-systolic volume was unchanged at rest but decreased significantly with exercise post PTCA (60 ± 36 ml pre vs 49 ± 32 ml post PTCA, p < 0.01). At rest, the PDFR was unchanged post PTCA (2.4 ± 0.9 end-diastolic volume (EDV)/sec pre vs 2.5 ± 0.8 EDV/sec post). During exercise, PDFR increased from 2.1 ± 0.7 EDV/sec pre PTCA to 2.5 ± 0.7 EDV/sec post PTCA (p < 0.02). In conclusion, in patients with coronary artery disease, successful PTCA improves global and regional systolic function during exercise. Diastolic function is improved during exercise, a fact not previously demonstrated.     

Left and right ventricular function during symptom-limited exercise in patients with isolated mitral stenosis

Ventricular function during exercise in patients with mitral stenosis has not been widely studied. Accordingly, 20 patients with isolated mitral stenosis were assessed during supine, symptom-limited equilibrium radionuclide ventriculographic studies. All patients had a normal left ventricular (LV) ejection fraction at rest (greater than or equal to 50 percent), and all were in sinus rhythm. Left ventricular ejection fraction rose (p less than 0.001) from 64 +/- 9 percent at rest to 74 +/- 11 percent during exercise. This normal response was due solely to a decrease (p less than 0.01) in exercise LV end-systolic volume. A significant (p less than 0.01) decrease in end-diastolic volume during exercise limited the increase in ejection fraction during exercise. The decrease in end-diastolic volume during exercise caused stroke volume to remain unchanged; cardiac output rose according to heart rate alone. Right ventricular (RV) ejection fraction did not rise with exercise due to an increase in end-systolic volume. With exercise, LV end-diastolic volume was smaller (p less than 0.05) with severe mitral stenosis compared to mild mitral stenosis. With exercise, RV ejection fraction was decreased (p less than 0.05) with severe compared to mild mitral stenosis. In conclusion, LV function during exercise is normal in patients with normal resting LV ejection fraction. A decrease in LV diastolic filling with exercise prevents a rise in stroke volume, and cardiac output increases by heart rate alone. With, exercise, RV ejection fraction does not rise, due to an increase in RV end-systolic volume.     

Right ventricular function at rest and during exercise in aortic and mitral valve disease

Right ventricular function at rest and during exercise was examined in a group of patients with symptomatic aortic or mitral valve disease, or both. The right ventricular ejection fraction was less than 45% in 22 of 36 patients at rest and in 12 of 17 subjects at symptom-limited, supine bicycle exercise. The right ventricular ejection fraction failed to increase more than 5% with exercise in 17 of 17 patients. The central venous pressure was greater than 5 mm Hg in 18 of 36 patients at rest and in 13 of 17 patients at maximal exercise. There was a significant inverse relation between rest right ventricular ejection fraction and mean pulmonary artery pressure (r = -0.47, p less than 0.05) and between rest right ventricular ejection fraction and mean central venous pressure (r = -0.39, p less than 0.05). There was no significant relation between the exercise values of these variables. In individual patients, the changes in right ventricular ejection fraction and pulmonary artery pressure with graded exercise were nonlinear. It is concluded that right ventricular function is not a simple function of pulmonary artery pressure at rest or during exercise in aortic and mitral valve disease. Less than one-quarter of the variation in right ventricular ejection fraction at rest can be explained by the variation in pulmonary artery pressure, and the finding of a normal (greater than 45%) right ventricular ejection fraction does not reliably exclude the possibility of pulmonary hypertension in a patient with valvular heart disease.     

Influence of nifedipine on left ventricular dysfunction at rest and during exercise

In order to determine the acute hemodynamic effect of nifedipineat rest and during a standardized supine bicycle exercise test(3 min, 50 W), 14 patients with left ventricular dysfunctionwere studied before and 60 min after taking 30 mg nifedipinesublingually. At rest (R) and during exercise (E), nifedipine produced a significantincrease in left ventricular systolic performance in terms ofstroke volume index (R: 33±6 to 38±4 ml/m², P<0.005;E: 32±5 to 37±6 ml/m², P<0.005) and cardiacindex (R: 2.9±0.4 to 3.6±0.5 l/min/m², P<0.001;E: 4.1±0.7 to 4.9±0.9 l/min/m², P<0.001) dueto a marked reduction in systemic vascular resistance (R: 1517±246to 1129±247 dynes s cm^–5, P<0.001; E: 1170±176to 908±129 dynes s cm^–5, P< 0.01). Pulmonary artery pressures did not change at rest, but droppedsignificantly during exercise, probably due to a shift in theleft ventricular pressure-volume relationship. The findingsof this study indicate that acute hemodynamic improvement canbe achieved by the sublingual use of nifedipine both at restand during exercise in patients with left ventricular dysfunction.Because the hemodynamic response in individual subjects mayvary, careful clinical observation or hemodynamic control isrecommended.     

Effects of verapamil on left ventricular diastolic function at rest and during isometric exercise in patients with hypertrophic cardiomyopathy

Ten patients with hypertrophic cardiomyopathy were examined with echocardiography before and during verapamil treatment to evaluate short-term and long-term effects of verapamil on left ventricular diastolic function. All patients were in sinus rhythm and in NYHA functional class I. Effects on filling and myocardial relaxation were documented by digitized echocardiography obtained at rest and during isometric exercise before treatment, after two weeks (short-term) and four months (long-term) treatment, respectively. At rest a significant decrease of the myocardial relaxation time was found during verapamil treatment. A few patients, however, returned to almost baseline conditions after an initial improvement. A small increase in the peak rate of dimension change, a parameter of filling, reached statistical significance at the end of the long-term treatment period. Isometric exercise did not induce any changes in the diastolic parameters during verapamil treatment. A positive effect of verapamil was thus seen on both myocardial relaxation and left ventricular filling, but only in resting conditions.     

Effects of molsidomine on global and regional left ventricular function at rest and during exercise in patients with angina pectoris

Although the antianginal properties of molsidomine are well-established, little is known about its effects on global and regional left ventricular dysfunction secondary to myocardial ischemia. In the present study, left ventricular performance was assessed by radionuclide ventriculography at rest and during exercise in 15 patients with coronary artery disease (CAD) and angina pectoris before and after the administration of 2 mg molsidomine sublingually. Gated blood pool studies were performed for evaluation of left ventricular ejection fraction (LVEF) and regional wall motion by analyzing amplitudes and phases of the first Fourier coefficient of regional time–activity curves. In contrast to normal subjects, during the control study period LVEF in patients with CAD decreased from 50.9% at rest to 42.7% during exercise (p<0.01). After molsidomine the resting values of LVEF increased slightly from 50.9% to 55.7% (p<0.05). Exercise values of LVEF increased from 42.7% to 51.3% (p<0.01). This is usually associated with amelioration of anginal pain and ischemic ST depression in the precordial ECG (0.15 mV vs. 0.09 mV; p<0.01). Before molsidomine, regional wall motion deteriorated from rest to exercise in 11 of 15 patients. These wall motion abnormalities usually expressed themselves as newly developed regions of left ventricular dysfunction (8 patients) or as accentuation of pre-existing contraction disturbances (3 patients). After molsidomine, regional wall motion did not show consistent changes at rest. Comparison during exercise showed enhanced regional function in 10 of the 15 patients after administration of the drug. At rest a slight but significant increase in heart rate was measured following molsidomine, whereas exercise heart rate remained unchanged. Only minor changes in systolic blood pressure occurred after molsidomine (rest, 143 mmHg vs. 134 mmHg; p<0.05; exercise, 177 mmHg vs. 174 mmHg; p>0.10). In conclusion, assessment of left ventricular performance at rest and during exercise in patients with CAD revealed significant improvement of global and regional left ventricular function, indicating reduction of myocardial ischemia. These effects may result primarily from reduction of left ventricular wall tension.     

Acute effects of alcohol on left ventricular function in healthy subjects at rest and during upright exercise

Six healthy men, aged 23 to 30 years, were studied by radionuclide angiocardiography at rest and at 2 submaximal exercise levels in the upright position during increasing alcohol intoxication. At light intoxication (serum ethanol 23 mmol/liter), the median value of left ventricular (LV) ejection fraction (EF) at rest decreased by 5%. At heavy intoxication (serum ethanol 45 mmol/liter), the median LVEF decreased at rest by 11% and during 75% submaximal exercise by 6%, heart rate at rest increased (median 81 vs 62 beats/min), and systolic blood pressure decreased during 50% submaximal exercise (median 145 vs 163 mm Hg). No significant changes of plasma epinephrine concentrations were recorded, whereas plasma norepinephrine concentrations were increased by 24% at rest during light intoxication and by 30 to 38% during heavy intoxication. No changes of LVEF and plasma catecholamine levels were recorded after ingestion of isovolumic, isocaloric drinks as compared with values obtained before intake. Thus, influences of ingestion per se and repeated investigations of LV function were excluded. These findings suggest that in healthy subjects alcohol intoxication causes a dose-dependent impairment of cardiac contractility. Compensatory mechanisms may account for a reduced influence during exercise.     

Value of exercise echocardiography in evaluating left ventricular systolic function in mitral stenosis

Exercise echocardiography was performed for 34 patients with mitral stenosis (MS) to evaluate left ventricular (LV) systolic function. The patients were categorized in three groups according to the work loads attained: Group I, 14 patients who attained 25 watts; Group II, 10 patients, 50 watts; and Group III, 10 patients, 75 watts. Among these groups, there were no statistical differences between the resting echocardiographic LV systolic function and their cardiac catheterization data. Resting LV end-diastolic and end-systolic dimensions (EDD and ESD) did not differ by group. During exercise, EDD and ESD decreased significantly in all groups, but ESD at the maximum exercise in Group I was greater than those of the other groups. The percent fractional shortening of the left ventricle (%FS) decreased significantly with exercise in Group I, while it increased significantly in the other groups. The mean velocity of circumferential fiber shortening (mean Vcf) increased significantly in all groups, but the extent was least in Group I. The exercise-induced changes in %FS (delta %FS) and mean Vcf (delta mean Vcf) correlated closely with exercise duration (r = 0.80, r = 0.73), but this was not the case in the mitral valve area. Postoperatively, exercise echocardiography was also performed for 14 patients with mitral stenosis; two of seven patients in Group I, four of five in Group II, and two in Group III showed significant improvement in exercise tolerance after surgery. However, the other six patients showed no change in their exercise tolerance. The former patients had positive values in delta %FS and more than 0.5 circ/sec in delta mean Vcf during pre-operative evaluations, while except one patient, those who did not improve had negative delta %FS values and less than 0.5 circ/sec in delta mean Vcf. It was concluded that the change in LV systolic function during exercise echocardiography reflects LV functional reserve in patients with MS, and provides valuable information for evaluating the severity of, indications for and benefits from surgery for MS.     

Effects of verapamil and nifedipine on left ventricular function at rest and during exercise in patients with prinzmetal's variant angina pectoris

To assess the effects of verapamil and nifedipine on left ventricular function at rest and during exercise in patients with Prinzmetal's variant angina pectoris, 10 patients (6 men and 4 women with a mean age of 52 years) with variant angina were each treated for 2 month periods with placebo, verapamil (400 ± 80 mg/day, mean ± standard deviation [SD]) and nifedipine (82 ± 31 mg/day). During the final week of each 2 month treatment period equilibrium gated blood pool scintigraphy was performed at rest and during exercise. At rest, heart rate during verapamil therapy was lower than during treatment with nifedipine; systolic blood pressure and left ventricular volumes and ejection fraction were similar for the three interventions. The maximal work load achieved was similar during placebo, verapamil and nifedipine therapy. At the maximal work load common to all three exercise studies, heart rate and systolic blood pressure were lower with verapamil than with placebo and nifedipine; ventricular volumes and ejection fraction were similar with the three agents. Thus, in patients with variant angina and a wide range of left ventricular function at rest, neither verapamil nor nifedipine significantly alters left ventricular volumes or ejection fraction at rest or during exercise.     

Effect of propranolol and disopyramide on left ventricular function at rest and during exercise in hypertrophic cardiomyopathy.

In 19 patients with hypertrophic cardiomyopathy (15 males, 4 females, mean age 49.2 +/- 10.8 years) left ventricular function was studied with radionuclide ventriculography at rest and during exercise in a crossover design without intervention and after disopyramide and propranolol treatment. 15 of the 19 patients had a resting or latent intraventricular gradient of more than 30 mm Hg. Left ventricular function at rest and during exercise was evaluated before medication, 90 min after oral administration of 200 mg disopyramide or 160 mg propranolol and after 3 weeks of oral therapy with disopyramide 200 mg 2 times a day or propranolol 80 mg 4 times a day. After long-term treatment with disopyramide, resting ejection fraction decreased from 72 +/- 12 to 69 +/- 14% (p less than 0.01) and peak ejection rate (PER) decreased from 3.46 +/- 135 to 3.24 +/- 65 end-diastolic volume (EDV).s-1 (p less than 0.01). Peak filling rate (PFR) at rest decreased from 3.01 +/- 0.8 to 2.77 +/- 0.63 EDV.s-1 (p less than 0.05). Time to peak filling rate (TPFR) at rest and during exercise after acute and chronic therapy did not change compared to control values. Acute and long-term administration of propranolol lead to a significant reduction in heart rate at rest and during exercise.(ABSTRACT TRUNCATED AT 250 WORDS)     

Left ventricular function at rest and during exercise in acute hypothyroidism

The effect of hypothyroidism on left ventricular function at rest and during exercise was studied in nine patients without demonstrable cardiovascular disease who had had total thyroidectomy and ablative radioiodine treatment for thyroid cancer. Radionuclide ventriculography and simultaneous right heart catheterisation were performed while the patients were hypothyroid two weeks after stopping triiodothyronine treatment (to permit routine screening for metastases) and while they were euthyroid on thyroxine replacement treatment. When the patients were hypothyroid, cardiac output, stroke volume, and end diastolic volume at rest were all lower and peripheral resistance was higher than when they were euthyroid. Pulmonary capillary wedge pressure, right atrial pressure, heart rate, left ventricular ejection fraction, and the systolic pressure:volume relation of the left ventricle, which was used as an estimate of the contractile state, were not significantly different when the patients were hypothyroid or euthyroid. During exercise, heart rate, cardiac output, end diastolic volume, and stroke volume were higher when the patients were euthyroid than when they were hypothyroid. Again, pulmonary capillary wedge pressure, ejection fraction, and the systolic pressure:volume relation were similar in both thyroid states. The data suggest that the alterations in cardiac performance seen in short term hypothyroidism are primarily related to changes in loading conditions and exercise heart rate; they do not suggest that acute thyroid hormone deficiency has a major effect on the contractile properties of the myocardium.     

Impaired left ventricular systolic function in mitral stenosis

OBJECTIVES: Left ventricular dysfunction is known in patients with mitral stenosis, but the incidence and cause remain unclear. The incidence and the factors related to left ventricular dysfunction were investigated in strictly selected patients with isolated mitral stenosis. METHODS: This study investigated 33 patients (5 males, 28 females) with isolated mitral stenosis aged 56 +/- 9 years. Left atrial dimension, left ventricular diastolic and systolic dimensions, mitral valve area, and mean transmitral pressure gradient were measured by echocardiography. Left ventricular ejection fraction was measured by Simpson's method. Patients were divided into two groups according to the ejection fraction (< 50%, > or = 50%). RESULTS: Seven patients (21%) had decreased left ventricular contraction and 26(79%) had normal contraction. The incidence of patients with atrial fibrillation in the low ejection fraction group was significantly higher than in the normal ejection fraction group(86% vs 31%, p < 0.01). There were no significant differences in the severity of mitral stenosis or other echocardiographic indices between the two groups. CONCLUSIONS: Low ejection fraction was present in 21% of patients with mitral stenosis. Since atrial fibrillation was more common in patients with low ejection fraction than those with normal ejection fraction, the rhythm disturbance may be related to the decreased left ventricular contraction.     

Pulmonary thallium uptake: correlation with systolic and diastolic left ventricular function at rest and during exercise

Quantified pulmonary 201-thallium uptake, assessed as pulmonary/myocardial ratios (PM) and body surface area-corrected absolute pulmonary uptake (Pc), was determined from single photon emission computed tomography studies in 22 normal subjects and 46 consecutive patients with coronary artery disease (CAD). By means of equilibrium radionuclide angiography (ERNA), ejection fraction (EF), peak ejection rate (PER) in end-diastolic volume (EDV/sec) and peak filling rate (PFR) in EDV/sec and stroke volume (SV/sec) units, PFR/PER ratio, and time to peak filling rate (TPFR) in milliseconds were computed at rest and during exercise (n = 35). Left ventricular response to exercise was assessed as delta EF, relative delta EF, delta EDV, and delta ESV. In normal subjects the PM ratios showed significant inverse correlation with PER at rest and with EF, PER, and PFRedv during exercise. For the left ventricular response to exercise, delta ESV showed significant correlation with the PM ratios. The body surface area-corrected pulmonary uptake values showed no correlation with any of the variables. In patients with CAD the PM ratios and Pc uptake showed significant inverse correlation with EF, PER, PFRedv and to exercise EF, exercise PER, and exercise PFRedv. For the left ventricular response to exercise, delta EF showed significant inverse correlation with the PM ratios but not with the Pc uptake. Neither in normal subjects nor in patients with CAD did any of the independent diastolic variables show significant correlation with the PM ratios or Pc values. Thus pulmonary thallium uptake is correlated with systolic left ventricular function at rest and during exercise in normal subjects and in patients with CAD but not with diastolic function. In normal subjects delta ESV and in patients with CAD, delta EF showed correlation with pulmonary thallium uptake.     

Immediate effects of percutaneous transvenous mitral commissurotomy on pulmonary hemodynamics at rest and during exercise in mitral stenosis.

Hemodynamics were evaluated during exercise in 33 patients with mitral stenosis who underwent percutaneous transvenous mitral commissurotomy (PTMC). PTMC was performed using an Inoue balloon. Each patient underwent a supine ergometer exercise test before and on the day after PTMC. Ergometer work load was started at 20 W and increased in increments of 20 W at 3-minute intervals until terminated by the patient's fatigue or shortness of breath. Mitral valve area increased by 0.8 +/- 0.4 cm2 (1.1 +/- 0.3 to 1.9 +/- 0.4 cm2, p less than 0.001). Mean mitral pressure gradient decreased (12 +/- 5 to 6 +/- 2 mm Hg, p less than 0.001). Pulmonary arterial pressure significantly decreased and the cardiac index significantly increased both at rest and during exercise after PTMC. Before PTMC, the increases in pulmonary arterial pressure, total pulmonary resistance and pulmonary arteriolar resistance during exercise were greater in patients with a mitral valve area less than 1.0 cm2 than in patients with an area greater than or equal to 1.0 cm2. After PTMC, total pulmonary resistance still increased during exercise. However, pulmonary arteriolar resistance did not change during exercise in patients with a mitral valve area greater than or equal to 1.5 cm2, whereas it increased in patients with an area less than 1.5 cm2. An enlarged mitral valve area greater than or equal to 1.5 cm2, which may prevent pulmonary vasoconstriction and permits a greater increase in pulmonary blood flow during exercise, is considered a good result immediately after PTMC.     

Effect of coronary collaterals on left ventricular function at rest and during stress

The influence of coronary collateral vessels on resting left ventricular function was investigated in 87 consecutive patients with complete coronary artery occlusion of at least one of the three major coronary vessels. The morphology of coronary and collateral circulation was evaluated by coronary arteriography. Left ventricular function was assessed by biplane ejection fraction and segmental wall motion was evaluated by hemiaxes shortening. Collaterals to occluded arteries were graded as good or poor, according to the caliber of the distal vessel segment. Patients were divided into those with good collaterals (n =35), and those with poor or absent collaterals (n = 52), furthermore, these two groups were subdivided according to the location of coronary artery occlusion. Collateralized single vessel occlusions were found more frequently than collateralized multiple vessel occlusions. Ejection fraction and segmental wall motion was significantly better in well collateralized occlusions than in poorly collateralized occlusions of LAD or RC and was normal or depressed only slightly if compared to 17 patients without heart disease. In contrast, total and regional myocardial function was severely depressed in poorly collateralized LAD or RC occlusion. Ventriculography after rapid ventricular pacing was performed in 12 of 87 patients with well collateralized or poorly collateralized LAD occlusion to evaluate to what extent coronary collaterals protect anterior wall motion during increased oxygen demand. Pacing induced a drastic fall of anterior wall motion in well collateralized segments whereas no change was found in poorly collateralized segments. Reviewing clinical data of two patient groups with comparable numbers and locations of occlusions revealed in the well collateralized group more severe angina (p < 0.001) and ST-segment changes during exercise (p < 0.01) than in the poorly collateralized group. The latter showed more severe dyspnoe (p < 0.01) and more histories of previous infarctions (p < 0.001). We conclude that well-developed collateral vessels to a complete occluded artery prevent severe asynergy at rest but not during stress.