Value of exercise test in detection of myocardial viability compared with thallium scintigraphy study

Management of patients who suffered acute myocardial infarction varies according to the absence or presence of myocardial viability. The study to assess the value of ST-segment elevation during exercise test in detection of viability after a first Q wave myocardial infarction treated with thrombolytic therapy within 12 hours of the onset of chest pain. Thirty patients were subjected to 2-D and M-mode full echocardiographic study, pre-dischrage symptom limited exercise test and pre-discharge rest thallium 201 scintigraphy study. The results showed no significant relation between the depressed left ventricular ejection fraction. and the preserved myocardial viability. None of the risk factors for ischemic heart disease towed any significant relation with the presence of myocardial viability. There was a high incidence of myocardial viability among patients documented by thallium study. ST segment elevation during exercise test occurred in 14 out of those 26 patients with viable myocardium 3.8%]. All those with ST segment elevation during exercise test showed bible myocardium by thallium. The study concluded that a pre-discharge symptom limited exercise test is considered to be of high specificity[100%] but of low sensitivity [53.8%] and low negative predictive value .2%]. The absence of ST segment elevation during exercise test at the Q related leads will require further sophisticated tests for detection of viability such as low dose dobutamine echo, thallium study or positron emission tomography

Egyptian coronary arteries: are they small?

Coronary size is one of the factors influencing the outcome of coronary interventions. This study was planned to screen main coronary arteries size in Egyptians in order to prove or disprove that Egyptians have small coronary arteries and to compare them to other races. 524 patients referred for coronary angiography were included in this study with no proximal local atheroma, spasm complete obstruction, stenosis nor multiple stenosis in the same vessel. Patients were divided into 3 age groups and were subjected to QCA for determination of the diameters of different segments of each coronary artery. The reference vessel diameter and cross sectional area were calculated for each, artery. In our study the influence of age, sex, hypertension [HTN] diabetes mellitus [DM], dyslipidemia and body surface area on coronary artery size were variable. The left main diameter was influenced by NTN, DM. and smoking; the left anterior descending diameter big age, HTN, and sex; the left circumflex diameter by age and RCA diameter by age and DM. Comparing our results to other races in different studies, we found the same range of Egyptian coronary artery size as other Caucasians, larger than Indo-Asians and comparable to the Americans. So, we concluded that Egyptians have large coronary arteries not small ones as we had expected

Altered left ventricular diastolic indices as an iscremic response to dipyridamole stress echocardiography: a comparative study with exercise ECG and coronary angiography

The most commonly used provocative test for IHD remains treadmill exercise testing. Echocardiography is one of the several techniques which have been used in conjunction with that test to enhance its diagnostic accuracy. In this study we used a pharmacological stressor [dipyridamole] rather than exercise to overcome the difficulty to maintain adequate views during exercise. Thirty patients coming for coronary angiography were subjected to both exercise EGG and dipyridamole echo before angigraphy. By dipyridamole echo, regional wall motion, wall motion score index [WMSI] and LV diastolic indices by Doppler were assessed before and after dipyridamole infusion [high dose]. According to the result of coronary angiography, the patients were classified to group I [nine patients with normal coronaries] and group II [21 patients with CAD]. The overall sensitivity and specificity of exercise ECG in patients with CAD were 71% and 78%, respectively while the sensitivity and specificity of dipyridamole echo were 86% and 100%. respectively. Our study revealed a significant increase in mean WMSI in group II with a positive correlation to the extent of CAD. Dipyridamoie echo also had the ability to predict LAD and RCA lesions with good sensitivity *86% and 83% respectively] but less for LCX [70%]. All patients with CAD arid positive dipyridamole echo showed a significant change in LV diastolic indices denoting acute relaxation abnormality during ischemia. We concluded that dipyridamole echo is more sensitive than the exercise ECG in the diagnosis and detecting the extent of CAD