Global myocardial perfusion and diastolic function are impaired to a similar extent in patients with type 2 diabetes mellitus and in patients with coronary artery disease--evaluation by contrast echocardiography and pulsed tissue Doppler.

AIMS/HYPOTHESIS: Using modern echocardiography, we quantified the extent of global myocardial function and perfusion abnormalities in patients with type 2 diabetes and compared this with the hypothetically similar extent of impairments in patients with coronary artery disease (CAD). SUBJECTS AND METHODS: This case-control study (66 patients) compared four age-matched groups: control, type 2 diabetic, CAD, and diabetic subjects with CAD (DCAD) and left ventricular ejection fraction >50%. CAD patients had 1-2 vessel disease. Diastolic and systolic myocardial velocities were assessed with pulsed tissue Doppler. Global myocardial perfusion was assessed with contrast echocardiography as indices of capillary blood volume and myocardial blood flow at maximal vasodilatation. In CAD and DCAD patients, functional and perfusion parameters were additionally assessed in the territory with a normal coronary angiogram reading, providing a model for comparison with the global data from control and diabetic patients. RESULTS: Comparing diabetic with control subjects, myocardial velocity at early diastole was impaired (8.8+/-1.8 vs 10.1+/-1.7 cm/s; p=0.02) and correlated inversely with age, HbA(1c) and pulse pressure (R (2)=0.761). Capillary blood volume (16.6+/-5.0 vs 24.4+/-4.9%) and blood flow (56+/-35 vs 114+/-40) were decreased (p=0.001). In CAD patients, myocardial velocity at early diastole was similarly decreased (p=0.02). CAD and DCAD patients were receiving more cardiovascular preventive therapy for the same extent of impaired global perfusion as in the less extensively treated diabetes group without CAD (p<0.002), but had superior perfusion of the 'normal' coronary territory than that group (p<0.05). CONCLUSIONS/INTERPRETATION: In patients with diabetes, global diastolic function and myocardial capillary blood volume and blood flow are impaired to the same extent as in patients with CAD. These impairments could form the basis of new therapeutic concepts.

QRS prolongation on the signal-averaged electrocardiogram versus ST-segment changes on the 12-lead electrocardiogram: which is the most sensitive electrocardiographic marker of myocardial ischemia?

BACKGROUND: ST-segment changes and QRS prolongation are electrocardiographic (ECG) markers of myocardial ischemia. HYPOTHESIS: This study was undertaken to investigate the appearance of QRS duration changes with or without concomitant ST-segment changes during a typical anginal episode. METHODS: For this purpose, 126 patients underwent 12-lead surface ECG and signal-averaged electrocardiogram (SAECG) during typical anginal pain as well as at the time the patient was asymptomatic. In both periods, QRS duration and ST-segment changes were evaluated. All patients underwent cardiac catheterization. RESULTS: Of the 126 patients, 108 (86%) had coronary artery disease (CAD), whereas the remaining 18 (14%) patients had normal coronary arteriograms. During typical anginal pain, 75 of the 108 (70%) patients with CAD and 2 of the 18 (11%) patients with normal coronary arteriograms developed QRS prolongation, whereas 60 of the 108 (56%) patients with CAD and 2 of the 18 (11%) patients with normal coronary vessels developed ST-segment changes. Thus, the sensitivities of QRS prolongation measured by SAECG and of ST-segment changes on the surface ECG for the detection of myocardial ischemia were found to be 70 and 56%, respectively, (p < 0.01), whereas the specificities were both found to be 89% (p = NS). CONCLUSIONS: During typical anginal pain, QRS prolongation on the SAECG is more sensitive than are ST-segment changes on the ECG for the detection of myocardial ischemia.