Search

Ventricular tachycardia may represent the first sign of an unknown cardiomyopathy; fewer data are available on the anatomical substrate of the arrhythmia. The aim of the study was to characterize better those patients who usually do not have haemodynamic impairment, but in whom the arrhythmia may be severely invalidating. To that purpose, two recent and sophisticated radiological methods were used, computed tomography (CT) and nuclear magnetic resonance (NMR); both methods allowed a precise characterization of the morphology and function of the right and left ventricle; a tissue analysis was performed that identified regions of lipomatous degeneration both in the right and the left ventricle, particularly with NMR.In conclusion, CT and particularly NMR appear to be able to reveal minimal changes suggestive of a right and/or left cardiomyopathy whose first manifestation is ventricular tachycardias. [ABSTRACT FROM PUBLISHER]

The effect of surgical versus medical treatment on long-term prognosis in angina at rest was assessed using the Cox regression model for survival analysis in 400 patients complaining of recurrent episodes of resting chest pain associated with transient repolarization changes. The surgical group included 185 patients, and the medical group 215. Surgically treated patients more frequently had two- and three-vessel disease, while single-vessel disease prevailed in medically treated patients (<0·01). No difference between the two groups was found in mean values of left ventricular end diastolic pressure and ejection fraction. Three variables were identified as independent predictors of prognosis in all patients: left ventricular end-diastolic pressure ( < 0·001), age > 45 years ( < 0·05), and number of diseased vessels ( < 0·05). Treatment modality did not result in different long-term survival in the entire population. However, patients with three-vessel disease had a better outcome with surgical than with medical therapy ( < 0·05). Although our conclusions must be tempered by consideration of the limitations of non-randomized studies, these results show that surgical treatment may improve survival in patients with angina at rest and three-vessel disease. [ABSTRACT FROM PUBLISHER]

The electrophysiologic effects of encainide were studied in 10 patients with Wolff–Parkinson– White syndrome after intravenous (1 mg kg in 60 minutes) and oral administration of two dose regimens (75 and 150 mg daily). Under control conditions atrial fibrillation (AF) with a rapid ventricular response was induced in all patients andatrioventricular reciprocating tachycardia (A VRT) in 9 patients. After intravenous encainide AF was no longer induced in 3/9 patients; in 3 of the remaining the accessory pathway (AP) was totally blocked and in the others the shortest RR interval increased from 213 ±6 to 297 ±91 ms and the mean RR interval from 293 ± 39 to 362 ± 79 ms. The lower dose of oral encainide prolonged the shortest RR interval from 206 ± 24 to 273 ± 64 ms and the mean RR interval from 280 ± 48 to 368 ±52 ms in 6 patients; in 2 cases no preexcitedbeats were recorded and in 1 AF was not inducible. After the higher dose of oral encainide A F was still inducible in 7/8 cases; in 3 the A P was blocked and in the others the shortest and mean RR intervals increased from 202 ±30 to 280 ± 24 ms and from 276 ±59 to 436 ± 80 ms, respectively. After intravenous encainide antegrade conduction over the A P was blocked in 4/9 patients and the antegrade effective refractory period (ERP) was prolonged in another 4. Oral encainide blocked A P conduction in 4 cases and prolonged ERP considerably in the others. Induction of A V RT was prevented in 1/8 patients after intravenous and in 5/9 patients after oral encainide; in the 4 patients in whom AVRTremained inducible cycle length increasedfrom 306±31 to 3 54 ±49 ms after intravenous encainide and to 392 ±46 ms after oral administration. All patients were discharged on encainide (mean maintenance dose, 127 mg daily) and followed for 21 ±7 months; no recurrence of AF was observed; two patients complained of transient mild side effects. These data show that in patients with Wolff-Parkinson- White syndrome encainide prolongs refractoriness and slows conduction over the AP; it prevents induction of AVRT and markedly slows ventricular response during AF, thus protecting patients against life-threatening arrhythmias [ABSTRACT FROM PUBLISHER]

The preliminary results of a prospective study undertaken in patients with a first episode of acute myocardial infarction are presented. The clinical, electrocardiographic and angiographic characteristics of 34 patients who developed early post-infarction angina (group I) were compared with those of 144 patients who remained asymptomatic after the acute infarct (group II). No difference was found between the two groups as to age, sex prevalence, risk factors, presence of stable angina before infarction, severe ventricular arrhythmias or transient congestive heart failure in CCU and peak CK value. Patients of group I had more frequently ecg signs of myocardial infarction in anterior leads (P < 0·01) than patients of group II. Exercise testing, performed by 23 patients of group I and by 140 patients of group II, was positive in 14 patients with early post-infarction angina and in 37 who remained as asymptomatic after the acute infarct (P < 0·01). The two groups had similar values of left ventricular end diastolic volume index, left ventricular end diastolic pressure and ejection fraction. Patients with early post-infarction angina however had more frequently double or triple vessel disease, while single vessel disease prevailed in group II patients. Although the follow-up period was limited (average 9 months), a higher incidence of cardiac complications was found in group I patients (P < 0·01). These data show that early post-infarction angina defines a high-risk subset of patients among those with recent myocardial infarction. A more aggressive approach, including thrombolytic therapy and coronary angioplasty, seems warranted. [ABSTRACT FROM PUBLISHER]

Over a five-year period 57 patients (pts) with sustained, recurrent, post-infarction ventricular tachycardia (VT) refractory to conventional antiarrhythmic treatment were evaluated. In 28 (49%) pts VT was controlled by amiodarone (A) in a dose of 3000 mg week. During long-term follow-up 5/28 (18%) pts died; no severe side-effects were observed with this dosage. In 17 of the 29 pts not controlled by this regimen, the dosage of A was increased to 6000–8000 mg week; short-term control of VT was achieved in 9/17 (53%) pts, but over a long-term follow-up 5/9 (56%) died and severe side-effects (11% polmonary fibrosis and 11% hepatitis) occurred in 22%. Twenty pts, resistant to a low (12 pts) or high (8 pts) doses of A, underwent map-guided surgical treatment. In conclusion A is superior to conventional drug's in the treatment of sustained, recurrent, post-infarction VT, but when high doses are necessary to prevent VT, long-term results are poor and severe side-effects frequent. In pts refractory to standard doses of A, map-guided surgery is the treatment of choice. [ABSTRACT FROM PUBLISHER]

A case of a patient with variant angina associated with severe ventricular tachyarrhythmias studied by continuous electrocardiographic and haemodynamic monitoring is reported. Severe ventricular arrhythmias developed both during maximal ST-segment elevation, in association with haemodynamic signs of acute ischaemic cardiac dysfunction and after nitroglycerin-induced reversion of ischaemia and return of the haemodynamic variables to the basal state. Thus, in this patient, ventricular arrhythmias during acute ischaemia could be related not only to acute vasospastic coronary occlusion but probably also to reperfusion after relief of coronary spasm. [ABSTRACT FROM PUBLISHER]

The purpose of this study was to focus on the clinical and angiographical characteristics of patients with crescendo angina (i.e. worsening angina, including rest pain occurring against the background of previously established angina) compared with those with angina of recent onset and to discuss the results of medical and surgical treatment in this particular subset of patients. One hundred and thirteen patients with a pattern of crescendo angina, admitted to our clinic between January 1976 and July 1983, showed a greater incidence of prior transmural myocardial infarction (P < 0·01), arterial hypertension (P < 0·01), multivessel disease (P < 0·01) and a lower value of left ventricular ejection fraction (P < 0·05) than 183 patients with angina of new onset observed during the same period of time. Although medical treatment was able to stabilize symptoms in 69 patients with crescendo angina, 44 underwent urgent coronary bypass surgery, while another 25 patients had to be operated on during the first six-month follow-up. At the end of this period the cumulative probability of failure for medical therapy was 62%. Survival curves up to five years showed that medically treated patients with crescendo angina had a worse long-term prognosis than patients with unstable angina of new onset (P<001). On the contrary, no difference in survival was found between the surgically treated patients in the two groups. [ABSTRACT FROM PUBLISHER]

Objective: To compare the ability of dobutamine and dipyridamole stress echocardiography to detect functional recovery of stunned but viable myocardial regions early after acute myocardial infarction, and to predict late functional recovery of the reperfusion salvaged myocardium within the infarct area.Methods: Within 10 d of acute myocardial infarction, 51 patients--30 anterior and 21 inferior, 44 Q wave and seven non-Q-wave infarction--were submitted to a dobutamine echocardiography test at low dose (5-10 micrograms/kg/min over 5 min) and high dose (20-40 micrograms/kg/min over 3 min) and to dipyridamole echocardiography test (0.56 mg/kg over 4 min + 0.28 mg/kg over 2 min) on different days and in random order, after interruption of any vasoactive drug. Resting echocardiography was repeated at two months in 41 of 51 patients (80%). Regional wall motion of the left ventricle was analysed in a semiquantitative manner on a 14-segment model. Viability was defined as improvement of one grade or more of at least two basally asynergic segments in the infarcted area.Results: Regional functional recovery was detected by low dose dobutamine in 38/51 patients (75%) and in 147/308 (48%) of basally asynergic segments, compared to 25/51 patients (49%; P < 0.001) and 78/308 segments (25%; P < 0.001) only identified by dipyridamole. Late spontaneous functional recovery was detected in 24/41 patients (59%) and in 78/254 basally asynergic segments (31%). The sensitivity of dobutamine and dipyridamole echocardiography for predicting spontaneous functional recovery was 72% and 51% respectively (P < 0.001), specificity 68% and 82% (P < 0.001), positive predictive value 50% and 56%, and negative predictive value 85% and 79%.Conclusions: In comparison with dipyridamole in patients with thrombolysed myocardial infarction, dobutamine induces regional functional recovery. This suggests that dobutamine is more sensitive in showing the presence of viable myocardium within the infarct zone, though it has a lower specificity in predicting delayed spontaneous functional recovery of non-contractile but still viable areas. [ABSTRACT FROM AUTHOR]

OBJECTIVE--To investigate whether the susceptibility to tolerance to glyceryl trinitrate is similar in different vascular beds in patients with chronic heart failure. PATIENTS--Twenty patients with heart failure underwent a continuous infusion of glyceryl trinitrate over 24 hours followed by administration of N-acetylcysteine (5 g intravenously) in a bolus. MAIN OUTCOME MEASURES--Haemodynamic measurements under control conditions, at peak titration of glyceryl trinitrate at 24 hours, and after N-acetylcysteine; plasma renin activity and packed cell volume. RESULTS--After 24 hours of infusion the acute reduction in right atrial pressure had largely waned, while pulmonary vascular resistance remained improved and systemic resistance, which was not reduced at peak titration, significantly decreased with respect to control conditions. The effects of N-acetylcysteine and hormonal responses were different in patients who did and did not develop tolerance to glyceryl trinitrate. CONCLUSIONS--The haemodynamic profile of glyceryl trinitrate changed substantially during the study from a predominantly venodilator action at peak titration to a predominantly arteriolar dilatation after 24 hours of infusion. The different effects of N-acetylcysteine and the different hormonal responses confirm the multifactorial pathogenesis of tolerance to glyceryl trinitrate. [ABSTRACT FROM PUBLISHER]