Diagnostic accuracy of dobutamine thallium-201 tomography in hypertensive patients with left ventricular hypertrophy

The noninvasive prognostic assessment of coronary artery disease [CAD] in hypertensive patients with left ventricular hypertrophy represents an unresolved task to date. In this study we investigate the diagnostic accuracy of dobutamine atropine thallium-201 scintigraphy in detection of the presence or absence of coronary artery disease in these patients. Methods and Forty hypertensive patients [55 +/- 7.5 years] with left ventricular hypertrophy documented by echocardiography were included in the study. Dobutamine stress thallium was performed for all patients.Graduated doses of dobutamine were infused Atropine [1mg] was given in patients not achieving 85% of age-predicted maximal heart rate. At peak stress, thallium [3 mci] was injected 4 hours later 1 mci was injected for redistribution images. All patients were subjected to coronary angiography within 2 months from the perfusion study. Systolic blood Pressure increased from [133 +/- 22 mmHg] to [150 +/- 20 mmHg] P=0.0001, heart rate increased from [75 +/- 12 bpm] to [138 +/- 9bpm]p=0.0001. The overall sensitivity, specificity, Positive predictive value negative predictive value and accuracy of thallium.201 SPECT for the diagnosis of coronary artery disease referred to coronary angiography were 84%, 85% 80%, 88% and 84% respectively. The sensitivity and specificity for individual vascular territories were also 76% and 93% for the left anterior descending artery 67% and 83% for the circumflex artery 70% and 97% for the right coronary artery. Dobutamine thalIium-201 Scintigraphy is a safe and feasible method for evaluation of coronary artery disease in hypertensive patients with left ventricular hypertrophy with good sensitivity and specificity for diagnosing and location of coronary artery disease and a diagnostic accuracy comparable to that in patients without hypertension

Mechanism of angina in patients with systemic hypertension and normal coronary angiogram

the purpose of this study was to investigate the changes in the coronary flow reserve in hypertensive patients with angina and normal coronary arteries, and its relation with coronary vasomotor response. the study population consisted of thirty hypertensive patients with angina and normal coronary angiogram [group I [non-LVH] n = 15 without left ventricular hypertrophy, group II [LVH] n = 15 with left ventricular hypertrophy and a matched healthy control group [group III n = 10]. Coronary velocity was monitored by means of transesophageal Doppler echocardiography basely and during infusion of [0.56 mg/kg per 4-minute] dipyridamole. Coronary flow reserve [CFR] was assessed as the ratio of mean diastolic velocity after dipyridamole and basal diastolic velocity. Coronary vasomotion was assessed by means of coronary catheterization as the changes in arterial caliber by acetylcholine and papaverine. Left ventricular mass, dimensions and function were measured by transthoracic echocardiography, Electrocardiography [ECG] changes were recorded by resting and exercise stress ECG. compared with the control group, CFR was decreased in both hypertensive groups [non-LVH = 1.56 +/- 0.22, LVH = 1.46 +/- 0.14, control = 3.49 +/- 0.60, P < 0.001]. The reduction in CFR depends on both an increase in resting coronary flow, and an impaired in maximal vasodilator capacity. Hypertensive patients who showed a positive exercise test have significant high resting mean diastolic coronary flow velocity [p < 0.01], and CFR showed positive correlation with exercise duration and rate-pressure product. Left ventricular mass had no effect on CFR, and wall stress was the major discriminating variable between non-LVH and LVH groups. imparied coronary flow reserve in hypertensive patients is the mechanism for the clinical syndrome of angina pectoris, abnormal electrocardigram but normal coronary arteries