Changes in echocardiographic left ventricular minor axis dimensions during exercise in patients with aortic stenosis

Effects of isometric exercise on the diastolic function in patients with severe aortic stenosis with or without coronary lesion

BACKGROUND

There is no literature evaluating the effect of exercise on patients with aortic stenosis, in which patients with and without coronary artery disease were assessed separately.

OBJECTIVE

To assess the effects of isometric exercise on the diastolic function in patients with aortic stenosis (AS).

METHODS

18 patients with AS, and 5 control patients were studied (group 1, G1). Patients with AS were divided in: group 2 (G2, n=10), without coronary lesion, and group 3 (G3, n=8), with coronary lesion. All patients underwent cardiac catheterization and performed isometric exercise until heart rate increased 32+/-9%. Left ventricular systolic pressure and end diastolic pressure (LVEDP), t1/2 (relaxation index), and the +dP/dt(max) were all measured.

RESULTS

The +dP/dt(max) increased in G1, G2, and G3 during exercise returning to their basal values once exercise had concluded. While exercising, the LVEDP increased in G1, G2 and G3, returning to its original baseline value only in G1 and G2. The t1/2 increased, while exercising, in G2 and G3, and continued to be elevated after the exercise in both groups although it was only statistically significant in G3. The control group did not show significant changes.

CONCLUSIONS

Isometric exercise decreases relaxation rate and increases LVEDP in patients with AS. After exercise, relaxation and LVEDP remained altered only in the patients with coronary lesion. The alteration in lusitropism and increased LVEDP after exercising suggest the presence of stunned myocardium.

Left ventricular diastolic response to exercise in valvular aortic stenosis

Exercise produces profound alterations in symptoms and hemodynamics in patients with valvular aortic stenosis (AS). Prior studies have demonstrated marked increases in late left ventricular (LV) diastolic filling pressure with exercise. Little information is available on the exercise response of indexes of early LV diastolic performance. Catheter-tip manometer recordings in 11 patients with AS and 5 age-matched controls were obtained at rest and with supine bicycle exercise at the time of cardiac catheterization. Pressure-derived indexes of LV diastolic performance, isovolumic relaxation rate, and diastolic interval data were examined. At rest, early (patients 22 +/- 6 mm Hg, controls 12 +/- 3 mm Hg; p < 0.01), minimal (patients 9 +/- 4 mm Hg, controls 4 +/- 1 mm Hg; p < 0.01), and late (patients 28 +/- 10 mm Hg, controls 13 +/- 3 mm Hg; p < 0.002) LV diastolic pressures were elevated in patients with AS. The time to onset of isovolumic relaxation (patients 422 +/- 31 ms, controls 363 +/- 40 ms; p < 0.01) and minimal LV diastolic pressure (patients 608 +/- 57 ms, controls 448 +/- 52 ms; p < 0.002) at rest were prolonged in patients with AS. With exercise, early (patients 45 +/- 14 mm Hg, controls 15 +/- 3 mm Hg; p < 0.002), minimal (patients 15 +/- 6 mm Hg, controls 2 +/- 1 mm Hg; p < 0.01), and late (patients 38 +/- 10 mm Hg, controls 18 +/- 5 mm Hg; p < 0.002) LV diastolic pressures were elevated, and the time to minimal LV diastolic pressure (patients 528 +/- 26 ms; controls 393 +/- 56 ms) and peak first derivative of LV pressure decline (-LV dP/dt) patients 395 +/- 41 ms, controls 326 +/- 59 ms) were prolonged in AS. Furthermore, patients with AS failed to comparably increase the rate of LV pressure decay and isovolumic relaxation with exercise. The LV diastolic response to exercise in patients with AS is distinguished from the control response by suboptimal and prolonged relaxation and a diminished rate of LV pressure decay. These abnormal responses in early diastolic function coupled with the known abnormal chamber distensibility in AS contribute to significant elevations in early, mid-, and late diastolic pressures with exercise.

Systemic and left ventricular responses to exercise stress in asymptomatic patients with valvular aortic stenosis

Patients with heart disease may have myocardial ischemia or left ventricular (LV) dysfunction without symptoms. The exercise responses of 14 asymptomatic patients with valvular aortic stenosis (AS) were studied using treadmill testing, thallium-201 scintigraphy and radionuclide angiography. Compared with age- and gender-matched control subjects, patients with AS demonstrated reduced exercise tolerance (10.7 +/- 2.5 vs 13.3 +/- 4.2 min; p = 0.06) and maximal oxygen consumption (26.7 +/- 6.3 vs 36.3 +/- 9.5 ml O2/min/kg; p = 0.004) associated with decreased peak systolic blood pressure response to exercise (177 +/- 18 vs 214 +/- 42 mm Hg; p less than 0.004). Ten of 14 patients developed ST-segment depression during exercise, only 3 of whom had reversible thallium defects. Patients with AS tended to have greater LV ejection fractions at rest (65 +/- 11 vs 58 +/- 7; p = 0.08) and significantly decreased early peak filling rates (4.8 +/- 1.3 vs 6.1 +/- 0.6 stroke volume/s; p = 0.003) compared with those of control subjects. During maximal supine exercise, patients with AS had less of an increase in ejection fraction (2 +/- 9 vs 15 +/- 7%; p less than 0.001) associated with a decrease in end-diastolic (-7 +/- 15 vs +5 +/- 16%; p = 0.06) and stroke (-6 +/- 17 vs +30 +/- 13%; p less than 0.001) volumes from baseline measurements.(ABSTRACT TRUNCATED AT 250 WORDS)