Comparison between low-dose dobutamine echocardiography and thallium-201 scintigraphy in the detection of myocardial viability in patients with recent myocardial infarction.

AIM: To compare the predictive value of thallium-201 single photon emission computed tomography (SPECT) scintigraphy (Sci) and low-dose dobutamine echocardiography (Dob) in predicting late recovery of dysfunctioning myocardium in patients with recent, uncomplicated myocardial infarction (MI). METHODS AND RESULTS: 19 patients (18 male, aged 58+/-8 years) with recent MI and ejection fraction <50% (35.5+/-8.3%) underwent 5-15 microg/kg per min Dob, rest-redistribution Sci and coronary angiography, respectively, 14+/-6, 16+/-7 and 17+/-5 days after MI. On an eleven-segment ventricular model devised to compare Dob and Sci segment by segment, each dysfunctioning ventricular segment was considered viable if it showed recovery of mechanical function at the echocardiographic follow-up, performed 6.3+/-1.5 months after revascularization (five PTCA, five GABG) or medical therapy. Among the 104 dysfunctioning segments, of which 26 (25%) showed recovery at follow-up, Dob and Sci gave a concordant response in 50 (48%, k = 0.13), correctly predicting the recovery (or not) of function in 42. Forty-two of 54 discordant responses were due to segments judged viable only by Sci and which had no recovery at follow-up (of these 37 were akinetic or severely hypokinetic at baseline). At the segment-by-segment analysis, the sensitivity, specificity, and accuracy in predicting recovery of function at follow-up were, respectively, 69, 88 and 84% for Dob as against 88, 36 and 49% for Sci (P<0.001 for both specificity and accuracy, P=NS for sensitivity). CONCLUSION: In patients with recent MI, the specificity of Dob in the detection of myocardium capable of late mechanical recovery is significantly higher with respect to Sci, whereas sensitivity is slightly, not significantly higher for the latter. It is conceivable that Sci detects viable myocardium even if it is transmurally limited to epicardial layers in segments with severely impaired mechanical function in which viability will not affect late recovery of function.

Systemic haemodynamics in renovascular hypertension: changes after revascularization with percutaneous transluminal angioplasty.

The systemic haemodynamic pattern and its changes after at least 6 months of successful percutaneous transluminal angioplasty (PTRA) was evaluated in a group of patients with renovascular hypertension (RVH). Fourteen patients, nine males and five females, aged 21 to 58 years, were studied; 12 had fibrodysplastic and two had atherosclerotic stenosing renal vascular lesions. Seven were cured and seven improved. Hypertension was characterized by increased plasma volume (PV) and total peripheral vascular resistance (TPR). Mean peripheral plasma renin activity (PRA) and 24-h urine aldosterone (UA) were elevated. However, the vasoconstriction did not appear to be related to the increased activity of the renin-angiotensin system. After at least 6 months of a successful PTRA, the fall in blood pressure (BP) was associated with a decrease in TPR; PV appeared normal, and PRA and UA became normal.

Effects of nadolol on systemic and renal hemodynamics in patients with renoparenchymal hypertension and various degrees of renal function.

It has been shown that renal hemodynamic changes following the decrease in cardiac output (CO) after therapy with beta-blockers may affect glomerular filtration rate (GFR), therefore limiting the effectiveness of these drugs; obviously more serious effects might be expected in nephropathic patients with previously reduced renal function. Recent clinical studies have demonstrated that nadolol, a non-cardioselective beta-blocker, preserves the renal blood flow (RBF) and the GFR. In this study, the drug was administered alone (80 mg once daily) for 2 months to 9 male renal parenchymal hypertensive patients with normal or moderately reduced renal function. Systemic and renal hemodynamics, plasma volume (PV), plasma renin activity (PRA) and urinary aldosterone excretion (UA) were evaluated before and after treatment. As blood pressure (BP) fell so did the cardiac index (4.27 +/- 1.05 l/min/m2 to 3.14 +/- 0.48 p less than 0.01), while the peripheral resistance index (TPRI) rose slightly (2257 +/- 658 to 2459 +/- 498 p = NS). No change in PV, RBF, GFR and renal vascular resistance was observed. An increasing trend in PRA (0.81 +/- 0.56 to 1.27 +/- 0.95 ng/ml/h) and no change in UA were observed. Our data show that nadolol was both well tolerated and effective in lowering BP, that it caused systemic hemodynamic alterations similar to those described for other beta-blockers, and preserved RBF and GFR also in renal hypertensive patients with reduced non-azotemic renal function.

[Supervision of the postoperative period in biliary shunt operations: validity of sequential hepato-biliary scintiphotography with 99mTc-HIDA]. / Controllo del decorso post-operatorio negli interventi di derivazione biliare: validita' della scintifotografia sequenziale epato-biliare con 99mTc-HIDA.

The Authors' aim was to assess the effectiveness of Sequential Scintiphotography of the Liver with 99mTc-HIDA (SSFH) in the evaluation of post operative jaundice, in operations of biliary derivation (43 observations in 28 patients). SSFH proved to be highly reliable even in comparison with more laborious procedures (such as Transhepatic Cholangiography), and superior to equally simple procedures such as Echo Tomography and Computerised Tomography, evidencing itself as the investigation of choice for the study of this pathology, especially in long-term follow-ups.