Attilio Reale

Evaluation of 10 QT prediction formulas in 881 middle-aged men from the seven countries study: Emphasis on the cubic root Fridericia's equation

In 881 middle-aged men from one Italian cohort of the Seven Countries Study, QT and RR intervals were measured in lead 2 from resting ECGs (25 mm/sec) and fitted separately with 10 mathematically different QT prediction formulas. The relative accuracy of fit to data was assessed from the minimum mean-squared residual and the minimum Akaike Information Criterion values. Using the Minnesota code, 588 men had normal (group 1) and 293 had abnormal (group 2) ECGs. A better fit to QT-RR data by all formulas was observed in group 1, compared with group 2. Among one-parameter equations in both groups, the cubic root Fridericias formula is better suited to fit the data than the Bazetts square root or other formulas. The former compares favorably with multiparameter equations or with the inverse relation and gives the best fit in group 2. Thus the cubic root equation might be more accurate than the square root or several complex formulas for correcting measured QT intervals for cardiac cycle length in middle-aged men.

Predictors of sudden death in idiopathic dilated cardiomyopathy

Survival in idiopathic dilated cardiomyopathy (IDC) has long been related only to left ventricular performance,1 yet there is now evidence that patients with IDC might die suddenly and unexpectedly.2,3 Although sudden death in IDC is most likely the result of a terminal malignant arrhythmia, the predictive value of complex ventricular ectopic complexes and of clinical and hemodynamic features is still controversial.4–6 We reviewed our experience with 104 consecutive patients with IDC to investigate which factors are most closely associated with sudden death.

Verapamil versus acebutolol for syndrome X

Abstract The precise mechanism responsible for angina pectoris in patients with syndrome X has not been completely identified. Recent evidence suggests that angina in these patients is probably due to an abnormal vasodilatory reserve of coronary microcirculation.1,2 This evidence and the clinical observation of an abnormally high pressure and heart rate response to low workload often seen in some patients with syndrome X suggest a role of an inappropriate sympathetic response in the pathogenesis of exercise-induced angina. To evaluate this aspect further, we carried out a randomized, double-blind, crossover study with acebutolol (a β1-specific blocking agent) and verapamil.

Comparison of left ventricular ejection fraction by magnetic resonance imaging and radionuclide ventriculography in idiopathic dilated cardiomyopathy.

To assess the validity of gated magnetic resonance imaging (MRI) in determining left ventricular (LV) ejection fraction (EF), MRI (Spin Echo, multislice-multiphase technique on the short-axis plane) was compared with equilibrium radionuclide ventriculography in 32 patients with idiopathic dilated cardiomyopathy. All patients underwent MRI and radionuclide ventriculography, performed consecutively on the same day (mean time interval between the 2 examinations: 40 minutes). Comparison with LVEF showed a high correlation (y = 0.79 X +3.51, r = 0.91; p less than 0.001). Mean difference between radionuclide ventriculography and MRI data was 1.7, with the 95% confidence interval 0.71 to 2.68: MRI slightly underestimated LVEF. MRI interobserver and intrapatient variability (assessed in 15 of 32 patients) showed a high correlation (r = 0.91, r = 0.98). In conclusion, data suggest that MRI, using the short-axis approach and the multislice-multiphase technique, is an accurate, noninvasive, highly reproducible method of evaluating LVEF in patients with idiopathic dilated cardiomyopathy.

Prevention of postischemic ventricular fibrillation late after right or left stellate ganglionectomy in dogs.

To gain insight into the differences in antiarrhythmic potential of right vs left stellate ganglionectomy, 72 dogs were randomized to either unilateral stellectomy or second intercostal space thoracotomy and left circumflex coronary arteriovenous pedicle occlusion was performed, without vagotomy, a mean of 8 weeks later under anesthesia. The type and timing of ventricular ectopic beats, including both nonsustained and sustained ventricular tachycardia and ventricular fibrillation, were investigated. Several covariates, including postischemic electrocardiographic changes, were considered. Both right and left stellate ganglionectomy reduced the incidence of early (0 to 10 min) (p = .004 and p = .001, respectively) and total (0 to 60 min) (p = .009 and p = .008, respectively) ischemia-induced ventricular fibrillation, and improved outcome (p = .0013 and p = .0012, respectively). Early sustained ventricular tachycardia was similarly reduced (p = .02) in both stellectomized groups. By contrast, neither the type nor the time distribution of the other forms of ventricular arrhythmias differed significantly among the randomized groups. The multivariate Coxs regression model showed that ST segment elevation at 3 min postocclusion, unilateral stellate ganglionectomy (either right or left), sex, and weight were significant independent predictors of the incidence of ventricular fibrillation during the occlusion period. Lower ST segment elevation and reduced incidence of sustained ventricular tachycardia in the early postischemic period might explain improved outcome in stellectomized dogs by Cox analysis. The side of intervention (either stellectomy or sham operation) did not influence survival; however, left-sided interventions were more effective than right-sided ones. These results confirm the previously reported antifibrillatory effect of left and indicate like effects of right stellate ganglionectomy in a randomized experimental study.

Acute Effects of Countershock Conversion of Atrial Fibrillation upon Right and Left Heart Hemodynamics

Right and left heart hemodynamics were studied in 12 patients with mitral valvular disease and atrial fibrillation before and immediately after external direct-current countershock resulting in restoration of normal sinus rhythm. The change of rhythm was accompanied by the following hemodynamic variations in the majority of cases: Systolic and mean pressures in the right and left ventricles and in the pulmonary and brachial arteries were not systematically altered, with a tendency, however, to a decrease in ejection pressures in the right heart and increase in the left heart. Mean right atrial and right ventricular end-diastolic pressures as well as left ventricular end-diastolic pressure decreased significantly. The behavior of the mean left atrial pressure appeared to be influenced by the degree of mitral valvular disease. Cardiac output and index and stroke volume and index increased; pulmonary vascular and systemic resistances decreased.The stroke work of the ventricles also increased in the majority of patients.An analysis of the changes in left ventricular end-diastolic pressure in relation to the left ventricular stroke work indicated that sinus rhythm resulted usually in a shift of the ventricularfunction curve to an area of improved performance.

Evaluation of the Contractile State of the Human Heart from the First Derivative of the Apexcardiogram

The first derivatives of the left ventricular pressure pulse (dp/dt LV) and of the apexcardiogram (&Dgr; ACG) were recorded 73 times in 45 subjects, and the time intervals from the peak of the R wave of the electrocardiogram to the peak of the derivatives (t-dp/dt LV and t-&Dgr; ACG) were determined under different circulatory conditions. These parameters express the duration of the development of maximum tension during isometric contraction of the ventricle. The values obtained from the left ventricular pressure pulse and from the ACG showed close correlation both at rest and after pharmacological interventions which enhanced or depressed the myocardial contractile state. During orciprenaline infusion, t-dp/dt LV and t-&Dgr; ACG were consistently shortened, while they increased in most cases after beta-adrenergic receptor blockade.Determination of the time to peak derivative of the ACG, a parameter so far unexplored, is proposed as a simple method of detecting changes in the myocardial contractile state in the intact human being.

Relation of complex ventricular arrhythmias to presenting features and prognosis in dilated cardiomyopathy

To evaluate whether complex ventricular arrhythmias relate to presenting features and prognosis of dilated cardiomyopathy, 104 patients were studied from 1977 to 1987. At diagnosis, the 19 patients with complex ventricular arrhythmias (18%), as compared to the 85 patients without (82%), had a higher incidence of palpitation (P less than 0.01), severe dyspnea (P less than 0.001) and atrial fibrillation (P less than 0.01). They showed also higher mean right atrial pressures (10 +/- 5 vs 6 +/- 4 mm Hg, P less than 0.001) and higher right ventricular end-diastolic pressures (11 +/- 4 vs. 7 +/- 4 mm Hg, P less than 0.001) than patients without complex ventricular arrhythmias. Histologic samples were collected from the 32 patients (31%) studied since 1984 and semiquantitatively graded. The 11 patients with complex ventricular arrhythmias showed a higher frequency of severe interstitial fibrosis than the 21 patients without (64% vs. 24%, P less than 0.05), but they were otherwise similar as to the frequency of marked myocellular hypertrophy, changes of myocardial regression, endocardial fibrosis, attenuation of myocytes, hyperplasia of smooth muscle cells and infiltration by inflammatory cells. During a follow-up of 3.8 +/- 3.5 years, 35 patients (34%) died. Mortality was 58% (11 out of 19) in patients with complex ventricular arrhythmias and 28% (24 out of 85) in patients without (P less than 0.025). These results show that complex ventricular arrhythmias in dilated cardiomyopathy are associated with impairment of function of the right heart and severe interstitial fibrosis of the left ventricle, rather than with left ventricular dysfunction. Presence of complex ventricular arrhythmias also seems to identify those at high risk for death.

Electrocardiographic correlates with left ventricular morphology in idiopathic dilated cardiomyopathy

The purpose of the present study was to verify whether the electrocardiographic pattern of patients with idiopathic dilated cardiomyopathy (IDC) might be useful in predicting measurements of left ventricular (LV) morphology. A total of 12 electrocardiographic criteria for LV enlargement were evaluated in 67 patients with IDC, aged 14 to 68 years (mean 48), and were correlated to LV wall thickness, volume and mass, as assessed at angiography (all patients) and echocardiography (50 patients). Linear regression analysis showed weak correlations between multiple electrocardiographic criteria and LV wall thickness, volume and mass. Multiple logistic regression analysis showed that total 12-lead QRS amplitude, voltage criteria of Sokolow and Lyon, overshoot and U-wave inversion were the variables significantly related to LV wall thickness, as assessed by angiography (r = 0.55, p less than 0.005) and echocardiography (r = 0.43, p less than 0.025). The sum of T/R-wave ratios, the RV6/RV5 ratio and the Romhilt-Estes score were predictors of LV end-diastolic volume, as determined by angiography (r = 0.83, p less than 0.001) and echocardiography (r = 0.77, p less than 0.005). Total 12-lead QRS amplitude and the sum of T/R-wave ratios were the only independent predictors of LV mass, either angiographically (r = 0.81, p less than 0.001) or echocardiographically measured (r = 0.71, p less than 0.025). It is concluded that a single electrocardiographic criterion for prediction of LV morphology in patients with IDC is barely effective. Multiple electrocardiographic criteria should be utilized to better predict LV mass and distinguish reliably between LV wall thickening and dilatation.

Mitral stenosis in childhood: Clinical and therapeutic aspects

Abstract Fifty-four patients with mitral stenosis, aged 8 to 15 years, are reported on. The symptomatology was constantly quite severe and all patients, except one, belonged to functional Classes III and IV. The electrocardiogram showed normal sinus rhythm in all, left atrial hypertrophy in 74 per cent, and right ventricular hypertrophy in 63 per cent. Radiologic heart size was only moderately increased in most cases. Catheterization of the right side of the heart, performed in 27 patients, revealed a high percentage of marked pulmonary hypertension, arteriolar resistance being relatively low in respect to total pulmonary resistance. Two patients were discharged, one because of acute endocarditis, the other because of normal hemodynamic data. Four patients died before operation. The other 48 patients underwent mitral valvotomy. At operation the valve was found to be markedly stenotic in most cases. There were no valvular calcifications. Valvotomy was estimated to be satisfactory in 96 per cent of the cases. In 4 patients, slight to moderate insufficiency was created. There was no operative mortality; one patient died 35 days after operation. Late postoperative clinical information was available in 38 patients, with a duration of follow-up from 1 to 8 years. Four patients died, after 1, 2, 5, and 512years. As for the other 34 patients, the clinical result was excellent in 17 and good in 13. One patient showed only slight improvement. After a period of initial benefit in 3 patients, there was a recurrence of symptoms, complete in one due to restenosis, partial in the others. The ECG showed regression of right ventricular hypertrophy in most cases, whereas the radiologic appearance remained mostly unchanged. There was only one instance of frank rheumatic reactivation. It is believed that mitral commissurotomy is clearly indicated in the childhood group, except in cases of acute carditis and/or overt cardiac failure.