sodium-pertechnetate-tc-99m and Mitral-Valve-Stenosis

To elucidate factors influencing responses of right ventricular systolic function to exercise stress, we evaluated the right ventricular ejection fraction and peak ejection rate with two different loading conditions, atrial septal defect and mitral stenosis, at rest and during exercise by means of gated equilibrium blood pool radionuclide ventriculography. In both atrial septal defect and mitral stenosis, strong correlations between changes in the right ventricular ejection fraction with exercise and pulmonary vascular resistance at rest (r = -0.97, p < 0.001; r = -0.86, p < 0.005: respectively) were found. Significant correlations between changes in the right ventricular peak ejection rate with exercise and pulmonary vascular resistance at rest (r = -0.85, p < 0.05; r = -0.75, p < 0.01: respectively) were found in atrial septal defect and mitral stenosis. Both the right ventricular ejection fraction and peak ejection rate were lower during exercise than at rest when pulmonary vascular resistance at rest was more than 200 dynes.sec.cm-5.m2 in both atrial septal defect and mitral stenosis. In conclusion, right ventricular systolic function responding to exercise stress was influenced by the pulmonary vascular resistance in both atrial septal defect and mitral stenosis.

Topics: Adult; Cardiac Catheterization; Erythrocytes; Exercise; Exercise Test; Female; Gated Blood-Pool Imaging; Heart Septal Defects, Atrial; Humans; Male; Middle Aged; Mitral Valve Stenosis; Pulmonary Artery; Pulmonary Veins; Sodium Pertechnetate Tc 99m; Stroke Volume; Systole; Vascular Resistance; Ventricular Function, Right

We observed 26 patients with mitral stenosis and 19 normal volunteers with exercise gated radionuclide angiography. Although no differences were seen between normal subjects and patients with mitral stenosis at rest in left (LV) and right (RV) ventricular ejection fraction, significant differences were found for exercise change in ejection fraction for both ventricles, exercise time, exercise workload, and the percent change in LV end-diastolic, LV stroke, and RV end-systolic counts (ESC). Because nearly all of the normals (18/19) had a decrease in RVESC, patients with stenosis were divided into two groups according to whether RVESC increased or decreased. Significant differences were found between these two groups for age, New York Heart Association class, prevalence of atrial fibrillation, echocardiographic mitral valve area, and prognosis, that is, number undergoing catheterization and surgery. We conclude that exercise radionuclide angiography does yield information that has significant clinical and prognostic value in patients with mitral stenosis.

Topics: Adult; Aged; Erythrocytes; Female; Humans; Male; Middle Aged; Mitral Valve Stenosis; Physical Exertion; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Stroke Volume

The results of 22 absolute left ventricular volume (LVV) determinations by a radionuclide (RN) method are compared to the results obtained by contrast ventriculography (CV). Another 10 patients were analysed in order to evaluate the interstudy, interobserver and intraobserver variances. Good correlation was shown between the RN and CV measurements of the end diastolic volume (EDV), end systolic volume (ESV), stroke volume (SV) and ejection fraction (EF), but the RN method overestimates the EDV and ESV. The EF was underestimated, but no difference could be shown for the SV. On the inter- and intraobserver levels, regression analysis yielded excellent correlation (r greater than 0.99 in all cases) with no statistically significant difference (P less than 0.05). The interstudy variance was minimal as indicated by regression analysis (r greater than 0.87) and no statistically significant difference (P less than 0.05) could be shown between studies. The results indicate that the RN method of LVV determination can be used in intervention studies over a limited period.

Topics: Adult; Aged; Coronary Disease; Humans; Middle Aged; Mitral Valve Stenosis; Radiography; Radionuclide Imaging; Reference Values; Sodium Pertechnetate Tc 99m; Stroke Volume

This is an account of 2 groups of 10 patients each who received Starr Edwards ball valves in either the mitral (M) or aortic (A) position on average 14.7 +/- 3 or 14.9 +/- 2.4 years ago, respectively. Non-invasive scintigraphic studies were performed using the first pass of 18 to 20 mCi 99 m-Technetium Pertechnetate. Enddiastolic and endsystolic volumes were found elevated at rest: (M) EDV 135 +/- 50 ml, ESV 63 +/- 30 ml; (A) EDV 163 +/- 41 ml, ESV 69 +/- 25 ml. The response to maximum exercise--during which the heart rate increased from 85 +/- 23 min-1 to 133 +/- 33 min-1--was abnormal, since none of the volumes changed significantly. During exercise, therefore, the increase of the cardiac output was totally heart rate dependent: (M) 6.1 +/- 2.3 to 9.3 +/- 2.3 l/min; (A) 7.0 +/- 1.9 to 10.9 +/- 3.1 l/min. The dynamics of the rapid diastolic filling rate of the left ventricle (RFR) and the mean pulmonary transit time (MTT) served as functional parameters of the Starr Edwards ball valves in the mitral position. The rapid filling rate increased from 205 +/- 98 to 321 +/- 58 ml/sec, whereas MTT decreased from 7.4 +/- 1.4 to 5.4 +/- 2.1 sec. In patients with aortic valve replacement the left ventricular ejection rate was assessed, it rose from 233 +/- 80 to 459 +/- 232 ml/sec. The significant changes of the parameters proved that the Starr Edwards ball valve mechanism functions satisfactorily 11 to 19 years post-operatively.

Topics: Aortic Valve Insufficiency; Aortic Valve Stenosis; Cardiac Output; Exercise Test; Follow-Up Studies; Heart Failure; Heart Valve Prosthesis; Hemodynamics; Humans; Mitral Valve Insufficiency; Mitral Valve Stenosis; Radionuclide Imaging; Sodium Pertechnetate Tc 99m