Screening for silent myocardial ischaemia in type 2 diabetic patients with additional atherogenic risk factors: applicability and accuracy of the exercise stress test.

OBJECTIVE: Coronary artery disease (CAD), a major cause of mortality in patients with type 2 diabetes (T2D), is often diagnosed late because of silent myocardial ischaemia (SMI). Exercise electrocardiogram testing (ECG) stress is the most utilized screening test for SMI. Its applicability and accuracy, which have never been reported in asymptomatic high-risk T2D patients, have been investigated in this study. DESIGN: A cross-sectional study with coronary angiography as the gold standard for detecting CAD was used. METHODS: Two hundred and six consecutive T2D patients, without symptoms and resting ECG signs of ischaemia but with peripheral vascular disease (PVD) and/or > or = two atherogenic factors, were studied. Ischaemia at ECG stress was indicated by horizontal or downsloping ST segment depression > or =1 mm at 0.08 s after the J point. CAD was defined by stenosis > or =70%. RESULTS: Only 141/206 (68%) patients had a diagnostic test: 27 (19%) tested positive and 114 (81%) tested negative. Coronary angiography in 71 patients (the 27 who tested positive and 44 randomly selected patients who tested negative) indicated a CAD prevalence of 29% and the ECG stress accuracy was 79%. 'False negative' patients (18%) had a higher prevalence (P<0.01) of long duration of diabetes and PVD. CONCLUSIONS: This is the first study which provides insights into the applicability and accuracy of ECG stress in screening SMI in high-risk patients with T2D. Due to the high prevalence of CAD, alternative screening tests in patients unable to perform the test and in those with a high chance of being 'false negative' should be looked for and validated.

Comparison of steerable continuous-wave versus pulsed-wave Doppler ultrasonography to renal artery angiography in diagnosing renal artery stenosis.

Pulsed-wave Doppler ultrasonography is widely used to noninvasively diagnose renal artery stenosis. The use of steerable continuous-wave Doppler has never been tested. We compared pulsed and steerable continuous-wave Doppler ultrasonography, demonstrating that although both methods are highly sensitive for severe stenoses, continuous-wave Doppler shows a better sensitivity for mild to moderate stenoses.

[Doppler flow-velocity analysis of the renal arteries in left ventricular dysfunction]. / Analisi della curva di flusso-velocità doppler delle arterie renali nella disfunzione ventricolare sinistra.

AIM OF THE STUDY: Chronic heart failure leads to renal hypoperfusion. Clinical methods for monitoring renal artery flow have several limitations. We analyzed the renal artery flow-velocity in patients with left ventricular dysfunction and normal controls by pulsed-wave (PW) color-guided Doppler technique. The relation between PW Doppler quantitative indexes and left ventricular ejection fraction (LVEF), creatinine clearance, and age, was also assessed. METHODS: We studied 53 patients with left ventricular dysfunction (LVEF by 2D echo < or = 40%) and no systemic hypertension, diabetes, parenchymal nephropathy, serum creatinine levels > 150 mmol/l, nor renal artery stenosis. Five patients were excluded for suboptimal renal artery PW Doppler recordings. Thus, the study group was constituted of 48 patients (mean age: 64 +/- 13 years). Twenty-eight normal subjects (mean age: 61 +/- 9 years) were the control group. By PW Doppler we measured the maximum (Vmax), the minimum (Vmin) and the mean (Vmean) velocities of both renal arteries. The resistivity index (RI), obtained from the formula (Vmax-Vmin)/ Vmax, and the pulsatility index (PI), obtained from the formula (Vmax-Vmin)/Vmed were calculated. Creatinine clearance was determined in each patient. RESULTS: RI and PI were greater in patients with left ventricular dysfunction than in normal controls. In normal controls, RI and PI were related to age (r: 0.63, p < 0.001; and r: 0.45, p < 0.05) and creatinine clearance (r: -0.44 and -0.40, respectively; both: p < 0.05), not to LVEF. In patients with left ventricular dysfunction, RI and PI were related to LVEF (r: -0.67 and -0.59; both: p < 0.001), other than to age (r: 0.57 and 0.55; both: p < 0.001) and creatinine clearance (r: -0.59, p < 0.001, and r = -0.46, p < 0.01, respectively). In this group, however, there was no sharp separation of RI and PI between patients with different degree of left ventricular dysfunction (LVEF < or = 30% and > 30%). CONCLUSIONS: In patients with left ventricular dysfunction, by renal artery PW Doppler analysis it is possible to detect noninvasively a reduction in regional flow-velocity and an increase in Doppler-derived vascular resistance indexes. These Doppler changes mainly depend on severity of left ventricular dysfunction and less on age of patients.

Regional wall motion analysis by dobutamine stess echocardiography to distinguish between ischemic and nonischemic dilated cardiomyopathy.

To distinguish between ischemic and nonischemic dilated cardiomyopathy (DCM), we studied 43 patients with left ventricular dysfunction (15 ischemic and 28 nonischemic detected by coronary angiography) by dobutamine stress echocardiography. At rest, there were more normal segments (p<0.001) and a trend toward more akinetic segments (p, not significant) per ischemic than per nonischemic DCM patient. However, either at rest or with low-dose dobutamine, individual data largely overlapped. At peak dose, in ischemic DCM, regional contraction worsened in many normal or dys-synergic regions at rest (in the latter case after improvement with low-dose dobutamine); in contrast, in nonischemic DCM, further mild improvement was observed in a variable number of left ventricular areas. Thus with peak-dose dobutamine, more akinetic and less normal segments were present per ischemic than per nonischemic DCM patient (both, p<0.001). A value of six or more akinetic segments was 80% sensitive and 96% specific for ischemic DCM. Our data show that analysis of regional contraction by dobutamine stress echocardiography can distinguish between ischemic and nonischemic DCM.

Systolic ejection murmurs in the elderly: aortic valve and carotid arteries echo-Doppler findings.

UNLABELLED: Two-dimensional echographic and color Doppler studies of the heart and carotid arteries (CA) were performed in 45 patients greater than sixty-five years old without aortic stenosis, 23 with (Group 1) and 22 without (group 2) precordial ejection systolic murmur (SM). Aortic cusps thickening was found in 11 Group 1 (48%) and 2 Group 2 (9%) patients (p less than 0.001). Aortic root and aortic arch size were similar in the two groups. Maximum aortic flow velocity was significantly greater in Group 1 (200 60 cm/sec) than in Group 2 (120 20 cm/sec) (p less than 0.001). Left ventricular outflow systolic maximum velocity was similar in the two groups. A bilateral neck murmur was heard in 10/23 Group 1 patients (43%); in this group, patients with cervical SM had a greater maximum aortic flow velocity than those without cervical SM (230 + 60 cm/sec vs 172 + 32 cm/sec, p less than 0.001). In Group 1, 3 patients had a cervical SM louder on one neck side; only in these 3 patients were ipsilateral obstructive CA plaques found. A unilateral neck SM was heard in 4/22 Group 2 patients (18%); in these 4, ipsilateral obstructive CA were found. CONCLUSIONS: (1) in the elderly, precordial ejection SM is related to mild increase in maximum aortic flow velocity and thickening of aortic cusps; (2) in patients with precordial SM radiated to both neck sides, maximum aortic flow velocity tends to be more markedly increased; (3) in patients with precordial SM, a cervical SM louder on one neck side should suggest coexistent ipsilateral CA stenosis.