ABSTRACT
The aim of this study was to compare two different quantitative methods used to determine left ventricular regional wall motions. Circumferential and radial methods were used to distinguish between normo- and hypokinesia of the 5 segments proposed by AHA for RAO position. One hundred ventriculograms were analyzed. Fifty cases with normal wall motion and ejection fraction greater than 55% were chosen as a base to enumerate normokinetic values of regional contractility. The other fifty cases represented hypokinesia of different segments. Respective values for the radial method were 61.42 vs 38.10 for antero-basal segment, 73.8 vs 58.5 for antero-lateral segment, 67.74 vs 42.5 for apical segment, 69.88 vs 47.70 for postero-lateral segment and 41.72 vs 33.4 for postero-lateral segment. The values obtained with the circumferential method were 12.27 vs 10.21, 20.06 vs 16.21, 22.19 vs 18.78, 17.08 vs 11.39 and 8.50 vs 8.15, respectively. These results suggest that the radical method allows to better differentiate between hypo- and normokinesia. Postero-basal segment proved to be most difficult to assess. Both methods fail to make a clear distinction in these cases.
Subject(s)
Gated Blood-Pool Imaging/methods , Ventricular Dysfunction, Left/diagnostic imaging , Evaluation Studies as Topic , Humans , Myocardial Contraction/physiology , Stroke Volume , Ventricular Function, LeftABSTRACT
We studied the correlation between changes in left ventricular filling dynamics induced by acute intravenous administration of verapamil and the changes in exercise tolerance induced by oral administration of the agent in 30 patients with hypertrophic cardiomyopathy. Diastolic cardiac function was measured by means of a nuclear stethoscope before and 10 min after intravenous administration of verapamil, 0.15 mg.kg-1 over 2 min. Treadmill exercise tests using a modified Bruce protocol were performed before the initiation of oral verapamil treatment and after 4 weeks of oral therapy at a dose of 320-360 mg.day-1 (mean +/- SD 332 +/- 17 mg.day-1). Peak filling rate (PFR) increased in 21 patients, 18 of whom (86%) also had an increase in exercise duration, PFR showed no increase in nine patients, eight of whom (89%) had no change in exercise duration (sensitivity 95%, specificity 73%, predictive value of the positive result 86%, predictive value of the negative result 89%). Acute changes in time from the beginning of rapid filling to PFR (t-PFR) and in left ventricular end-diastolic volume (EDV) were less useful in predicting improvement in exercise tolerance. In 19 patients the changes in PFR and EDV paralleled. Twelve of the 13 patients (92%) with an increase in both parameters also had an increase in exercise duration, whereas all six in whom these parameters were reduced showed no increase in exercise duration (sensitivity 100%, specificity 86%, predictive value of positive results 92%, and predictive value of negative results 100%).(ABSTRACT TRUNCATED AT 250 WORDS)
Subject(s)
Cardiomyopathy, Hypertrophic/drug therapy , Diastole/drug effects , Exercise Tolerance/drug effects , Ventricular Function, Left/drug effects , Verapamil/pharmacology , Administration, Oral , Adult , Aged , Cardiomyopathy, Hypertrophic/complications , Cardiomyopathy, Hypertrophic/physiopathology , Female , Heart Rate/drug effects , Heart Ventricles/diagnostic imaging , Heart Ventricles/drug effects , Heart Ventricles/physiopathology , Humans , Injections, Intravenous , Male , Middle Aged , Predictive Value of Tests , Radionuclide Imaging , Sensitivity and Specificity , Ventricular Outflow Obstruction/etiology , Ventricular Outflow Obstruction/physiopathology , Verapamil/therapeutic useABSTRACT
In order to assess the accuracy of pulmonary time-activity curves obtained at bedside with a single scintillation probe and Technetium-99m-labelled erythrocytes, pulmonary to systemic flow ratio (Qp:Qs) was calculated for radionuclide and hemodynamic investigations in 104 patients with suspected intracardiac left to right shunts. Cardiac catheterization confirmed the presence of shunts in 76 patients. Pulmonary time-activity curve was 100% sensitive, 88% specific, and 96% accurate in detecting the shunt. Correlation between the radionuclide and hemodynamic Qp:Qs was excellent (r = 0.93). Results were classified in four quantitative categories according to the Qp:Qs values. In 76 patients (73%) radionuclide and hemodynamic data fell in the same category. We conclude that radionuclide pulmonary time-activity curves generated with a scintillation probe is a reliable method in quantitative assessment of intracardiac left to right shunts.
