Biomedical subjects

Giovanni B Perego

Publications and source records attributed to Giovanni B Perego.

4 recordsLinked to original sources

PubMed2006

Prediction of response to cardiac resynchronization therapy: the selection of candidates for CRT (SCART) study.

BACKGROUND: The aim of this study was to evaluate the ability of baseline clinical and echocardiographic parameters to predict a positive response to CRT. METHODS: We analyzed 6-month data from the first 133 consecutive patients enrolled in a multicenter prospective study. These patients had symptomatic heart failure (HF) refractory to pharmacological therapy (NYHA class II-IV), left ventricular ejection fraction (LVEF) < or =35%, and prespecified electrocardiographic, echocardiographic or tissue Doppler imaging markers of left ventricular (LV) dyssynchrony. RESULTS: After a follow-up period of 6 months, 1 patient died and 13 were hospitalized for worsening HF. There were significant (P < 0.01) clinical, functional, and echocardiographic improvements that included: New York heart Association Class, Quality-of-Life Score, QRS duration, LVEF, LV end-diastolic and end-systolic diameter (LVESD), and severity of mitral regurgitation A positive response was documented in 90/133 (68%) patients who presented an improved clinical composite score associated to an increase in LVEF > or = 5 units. A multivariate analysis identified that a smaller LVESD (OR = 0.957, 95% CI 0.920-0.996; P = 0.030) and longer interventricular mechanical delay (IVMD) (OR = 1.017, 95% CI 1.005-1.029, P = 0.007) as independent predictors of a positive response. Receiver-operating curve analysis showed that a positive response to CRT may be predicted in patients with IVMD > 44 ms (with a sensitivity of 66% and a specificity of 55%) or with LVESD < 60 mm (with a sensitivity of 66% and a specificity of 61%). CONCLUSIONS: Our results confirm the limited value of QRS duration in the selection of patients for CRT. A less-advanced stage of disease and echocardiographic evidence of interventricular dyssynchrony demonstrated to predict response to CRT, while intraventricular dyssynchrony did not predict response.

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PubMed2005

Reverse ventricular remodeling and improved functional capacity after ventricular resynchronization in advanced heart failure.

BACKGROUND: Ventricular resynchronization is a non-pharmacological treatment for advanced heart failure refractory to drug therapy and with intraventricular conduction delay. We describe the time course of echocardiographic and functional recovery after resynchronization in 31 patients (mean age 67 +/- 8 years). METHODS: We evaluated NYHA class, echocardiogram, respiratory function, and cardiopulmonary test before pacemaker implantation (baseline), after 1-3 months (short-term evaluation), and 10-15 months afterwards (long-term evaluation, n = 21 patients). Mortality at 1 year was considered. RESULTS: Both at short and long-term, patients improved NYHA class, ventricular function, and ventricular volumes. Already at short-term, we observed an increase in oxygen consumption at peak exercise (12.6 +/- 0.6 vs 10.5 +/- 0.5 ml/kg/min), oxygen consumption at anaerobic threshold (9.8 +/- 0.6 vs 8.3 +/- 0.6 ml/kg/min) and oxygen pulse (8.3 +/- 0.5 vs 7.5 +/- 0.5 ml/beat). Ventilatory efficacy (VE/VCO2 slope) and alveolo-capillary diffusion (estimated by the measurement of lung diffusion capacity for carbon monoxide - DLCO) improved only at long-term (VE/VCO2: 40.7 +/- 1.6 vs 45.3 +/- 1.8; DLCO: 70.3 +/- 2.7 vs 59.4 +/- 5.9% of predicted, p = 0.05). The 1-year mortality was 9.7%. CONCLUSIONS: Ventricular resynchronization is linked to a fast and prolonged recovery of NYHA class, echocardiographic variables and stress tolerance. The improvement of indexes known to carry a prognostic value confirms that ventricular resynchronization can positively interfere with the evolution of the disease.

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PubMed2003

Simultaneous vs. sequential biventricular pacing in dilated cardiomyopathy: an acute hemodynamic study.

AIMS: Simultaneous biventricular pacing improves left ventricular (LV) systolic performance in patients with dilated cardiomyopathy and intraventricular conduction delay. We tested the hypothesis that further improvements can be obtained using sequential biventricular pacing by optimizing both atrioventricular and interventricular delays. METHODS AND RESULTS: In 12 patients, LV pressure, right ventricular (RV) pressure and respective rates of change of pressure (dP/dt) were acutely measured during biventricular pacing with different atrioventricular and interventricular (VVi) intervals ranging from -60 to +40 ms. The average increase vs. baseline in maximum LV dP/dt was higher for sequential than for simultaneous biventricular pacing (VDD mode: 35+/-20 vs. 29+/-18%, P<0.01; DDD mode: 38+/-23 vs. 34+/-25%, P<0.01), with a minority of patients accounting for most of the difference. The mean optimal VVi was -25+/-21 ms in VDD mode and -25+/-26 ms in DDD mode. With these settings, RV dP/dt was not significantly different from baseline. QRS shortening was not predictive of LV dP/dt increase. CONCLUSION: A significant increase of LV dP/dt with no change in RV dP/dt can be obtained by sequential biventricular pacing as compared to simultaneous biventricular pacing. The highest LV dP/dt is achieved when LV is stimulated before RV. The hemodynamic advantage might be of clinical significance in selected cases.

Aged↗

PubMed2003

Long-term treatment with the beta-blocker carvedilol restores autonomic tone and responsiveness in patients with moderate heart failure.

The authors performed two studies on the effects of carvedilol on autonomic tone and responsiveness in patients with heart failure. In study 1, the autonomic responses of 25 patients (age, 60 years+/-2; New York Heart Association [NYHA] class, 2.6+/-0.5; pVO2, 16.6 mL/Kg/min+/-1.1) treated with angiotensin-converting enzyme inhibitors, diuretics, and carvedilol (38.0 mg/d+/-2.5) were compared to those of 25 patients of similar age, therapy, NYHA class, and pVO2 in whom carvedilol was not yet administered. In study 2, autonomic tone and responsiveness were studied in 20 patients (age, 57 years+/-9; NYHA class, 2.5+/-0.2; pVO2, 15.6 mL/Kg/min+/-3.4), before and 6 months after additional carvedilol treatment (40.0 mg/d+/-12.5). Autonomic evaluation was performed with autoregressive power spectral analysis of RR variability during 10 minutes of supine rest (control), breathing 20 times per minute (vagal stimulus), and standing (sympathetic activation). The ratio between low-frequency (LF) and high-frequency (HF) components of the autospectra indicated the sympathovagal interaction. In study 1, spectral analysis in controls showed sympathetic hyperactivity which was blunted in patients receiving carvedilol (LF/HF ratio: 10.4+/-1.4 vs. 7.0+/-1.1; P<0.05) who responded to vagal and adrenergic stimuli (LF/HF, -35% with regular breathing and 72% standing). In study 2, left ventricular function, volumes, and exercise performance improved with carvedilol (EF, 31%; EDLV volume, -22%; pVO2, 11%; P<0.05). Sympathetic hyperactivity in control was reduced (LF/HF ratio, 4.9+/-0.8 from 7.9+/-1.3; P<0.05), whereas a response to vagal and adrenergic activation on breathing and standing reemerged (LF/HF ratio, -31% during regular breathing and 88% on standing). Therefore, combined autonomic and hemodynamic effects may determine the favorable effects of beta-blockers in heart failure.

Adrenergic beta-Antagonists↗