Comparative study of three non-invasive stress tests: Exercise electrocardiography, exercise echocardiography, and dipyridamole echocardiography for assessment of myocardial infarction

Three noninvasive stress tests were compared as regards their value in predicting multivessel coronary artery disease in post-myocardial infarction patients. The study included 16 patients with MI after at least 3 weeks from the acute attack. All had Q-wave infarction except one with subendocardial infarction. Exercise electrocardiography [Ex. ECG], exercise echocardiography [EEC] and dipyridamole echocardiography [DEC], as well as coronary angiography, were done to all patients. A 16-segment model of the left ventricle was used to derive a wall motion score index [WM-SI]. On EEC, 11 patients had WM-SI >1.5 with remote asynergy, and 5 WM-SI <1.5 without remote asynergy. DEC did not prove valuable in the study, it was negative in all patients. The following were found good predictors of multivessel CAD: Exercise induced ST depression >/2 mm, exercise induced transient remote asynergy usually with WM-SI >1.5, positive exercise ECG with duration <6 minutes

Assessment of left ventricular dilatation during the three months after acute myocardial infarction: an echo-doppler study

Left ventricular dilatation and remodeling is shown to start within days of transmural myocardial infarction [TMI]. Whether this process stabilizes, continues or regresses, thereafter, and whether therapy with angiotensin-coverting enzyme inhibitor alters this process, is in need of further study. Thitry patients with TMI were studied with echo-Doppler, one recording was done in first week after infarction and second recording 3 months later. Ten patients had inferior MI and 20 had anteroseptal or extensive anterior MI. They were also classified into 3 groups, 10 each, according to drug therapy [captopril group, atenolol group, nifedipine group]. The anterior segment, posterior segment and total circumference of the left ventricle were studied in the short axis view at level of papillary muscle. Eleven patients revealed increase in LV circumference [dilatation] more than 7% of the original diameter. This progression of LV size was due to dilatation of both the infarcted zone [expansion] and the uninfarcted segment. Patients treated with captopril or atenolol showed a tendency of reducing the progression of LV dilatation

Value of electrophysiologic study in Mitral Valve Prolapse Syndrome

The results of programmed ventricular stimulation in 18 patients who had mitral valve prolapse [MVP] and no other structural disease, with symptoms, suggestive of arrhythmia, were reported. All were confirmed to have MVP by 2D echo. The electrocardiogram demonstrated ST-T wave abnormalities in 6, QTc prolongation in 6, supraventricular tachycardia [SVT] was recorded in 2 patients. Holter recording was applied to 16 out of the 18 patients. It revealed SVT in the patients with clinically documented SVT, period of asystole in one, sinus bradycardia in 4. Electrophysiologic study was done to all patients, their bundle recording and estimation of A-H, H-V, sinus node recovery time [SNRT] were recorded. Stimulation of R. artium, R. ventricular apex and outflow tract with single and double extrastimuli were done. Results indicated that repetitive ventricular responses appeared in 8, induction of SVT in 2. VT was not induced in any patient. Correlation of symptoms, MR, and Holter data to EPS results revealed that EPS did not induce arrhythmia that were not detected by Holter. Thus, Holter recording is equally informative as EPS in patients with MVP. EPS in MVP is not needed if there are no frank syncope or serious arrhythmia that is not solved by Holter alone

Role of left ventricular dilatation as a predictor of outcome after aortic valve replacement

Aortic valve replacement [AVR] prolongs life and reduces symptoms, but it does not result in normal postoperative ventricular performance in all patients. The purpose of this work was to evaluate the role of left ventricular dilatation as a predictor of outcome after AVR. Two groups of patients were studied: Group 1, composed of 14 patients with dilated left ventricle, and group 2, composed of 7 patients with normal left ventricular parameters. AVR was performed for all patients using St. Vincent aortic prosthesis. Echo-Doppler study was done preoperatively, early postoperative and during follow up at 3-month interval. The EF percentage change in group 1 was 21% and 0% in group 2. The LVEDD percentage change was 16.6% in group 1 and 9.4% in group 2. The LVESD percentage change was 26% in group 1 and 9.8% in group 2. The LVM percentage change in group 1 was 31% and 26% in group 2. It was concluded that even if AVR is delayed there is a chance of good left ventricular improvement postoperatively

Serum potassium levels after moderate exercise in cardiac patients and normal individuals

This study is designed to investigate the effects of exercise on potassium ion, in view of the significant influence of K+ on the heart. We studied 2 groups; the first consisted of 24 patients with known coronary heart disease who had been under our care during the previous three years and who had been in good condition. The second group consisted of 25 healthy volunteers. Postexercise mean K+ levels were higher in both groups than resting levels. Moreover, 3 of the coronary artery disease 24 patients experienced major potassium elevation of 0.9 m mol/L or more, while 6 of the 25 healthy volunteers had the same magnitude of elevation. Interestingly, none of the subjects of the study showed ECG changes during the K+ elevation. This means that coronary artery disease patients who have been clinically stable for reasonable periods may not be vulnerable to conduction or rhythmicity disturbances during moderate exercise. However, to support this conclusion, larger numbers of patients should be included in a similar study

new score for prediction of perioperative myocardial infarction in coronary bypass surgery: comparison of two different centers

The incidence of perioperative myocardial infarction [PMI] after coronary artery bypass grafting [CABG] ranges from 2% to 25%. This study was made to determine the incidence and predictive factors of PMI in two hospitals: 361 patients in one international, Clevel and Clinic Foundation [CCF], and 70 patients in the relatively new Erfan Hospital, Jeddah [ERF]. PMI was judged by the presence of new Q wave MI, enzyme changes more than double normal, as well as unequivocal ST raising. PMI was found in 3.2% [20/631] in CCF and 8.6% [6/70] in ERF [P = 0.001]. Factors that were found to be statistically significant in predicting occurrence of PMI included left main coronary disease [LMT], LV dysfunction, recent MI or unstable angina, cross-clamp time greater than 60 min [CxT] and bypass time greater than 120 min [ByT], so we designed a new score system depending on 7 factors, each is given one mark: LV dysfunction, LMT, number of grafts 3 or more, recent MI or unstable angina, CxT, ByT, and CxT per graft greater than 30 minutes