ABSTRACT
One-hundred and nine patients undergoing coronary artery bypass grafting were randomized to seven groups according to cardioplegia technique (5 types) and right coronary patho-anatomy (2 types). There were no major intergroup differences in postoperative outcome. Conduction disturbances developed in 26 patients, also without intergroup difference. Factors predictive of conduction disturbances were studied by univariate and multivariate analyses. Patients with such disturbances had lower myocardial temperatures than the others and more often postoperative atrial fibrillation (10/26 vs 15/83, p < 0.05). Comparison of this case series with a prospective study from our hospital in 1988-1989 showed that myocardial protection was superior in the present study. The incidence of right bundle branch block was similar in the two studies (24% vs 23%), but that of left-side conduction disturbances (bundle branch or fascicular block) was dramatically reduced (19% vs 1%, p < 0.0001) concomitantly with improved myocardial protection, indicating that development of a left-side conduction disturbance is associated with myocardial injury.
Subject(s)
Arrhythmias, Cardiac/etiology , Coronary Artery Bypass , Heart Arrest, Induced/methods , Heart Conduction System , Bundle-Branch Block/etiology , Female , Humans , Male , Middle AgedABSTRACT
In an investigation of factors influencing the occurrence of supraventricular arrhythmias, ninety-eight patients were randomized to receive either cold blood (n = 49) or cold crystalloid (n = 49) cardioplegia during an elective coronary artery bypass grafting operation and were followed for seven days for the development of postoperative atrial fibrillation (AF). Twenty-one patients in the blood-cardioplegia group and nine in the crystalloid-cardioplegia group developed AF (p < 0.01). The patients who developed AF had smaller CK-MB enzyme leaks one hour after the operation (57 +/- 26 iu/L for AF vs 70 +/- 30 iu/L for normal rhythm, p < 0.05), and more often spontaneous beating after cross-clamp release (37% vs 15%, p < 0.05), which indicates that AF was not associated with poor ventricular myocardial protection or conduction system protection. The lesser amount of cardioprotective solution with AF patients (3551 +/- 1585 ml vs 4064 +/- 1562 ml, p < 0.05) and the time of onset of atrial fibrillation (4.0 +/- 1.8 postop. days) indicate that AF is probably caused at least partly by a reperfusion injury at the atrial level. The possibility of atrial fibrillation can be reduced by giving sufficient cardioplegia and giving beta-blocking medicine after the operation.
Subject(s)
Atrial Fibrillation/etiology , Blood , Coronary Artery Bypass , Heart Arrest, Induced/adverse effects , Heart Arrest, Induced/methods , Plasma Substitutes/adverse effects , Atrial Fibrillation/enzymology , Atrial Fibrillation/prevention & control , Creatine Kinase/blood , Crystalloid Solutions , Female , Humans , Isoenzymes , Isotonic Solutions , Male , Middle Aged , Myocardial Reperfusion Injury/etiology , Time FactorsABSTRACT
Postoperative conduction disturbances after coronary artery bypass grafting were analyzed in 100 patients who randomly received either blood or crystalloid cardioplegia. Conduction disturbances, mostly transient, developed after termination of cardiopulmonary bypass in 30 of the 100 patients--15 in either group. Ischaemia appeared to be a major determinant for conduction disturbances. Previous inferior myocardial infarction and stenosis of the right coronary artery both exposed the patient to risk of right bundle branch block.
Subject(s)
Blood Transfusion , Coronary Artery Bypass/methods , Heart Arrest, Induced/methods , Heart Block/epidemiology , Plasma Substitutes/administration & dosage , Postoperative Complications/epidemiology , Body Temperature , Creatine Kinase/analysis , Crystalloid Solutions , Female , Follow-Up Studies , Heart Block/etiology , Heart Block/metabolism , Humans , Isoenzymes , Isotonic Solutions , Male , Middle Aged , Postoperative Care , Postoperative Complications/etiology , Postoperative Complications/metabolism , Preoperative Care , Prospective Studies , Rehydration Solutions/administration & dosageABSTRACT
The antiarrhythmic efficacy and tolerability of encainide and quinidine were compared in an open-design study in which 50 patients with recurrent supraventricular tachyarrhythmias received intravenous encainide in an initial phase and oral encainide and quinidine in a subsequent, randomized crossover phase. Oral encainide (75 to 200 mg/day), administered to 47 patients for an average of 4.7 months, was effective in 77%, and oral quinidine (1,200 mg/day), administered to 44 patients for an average of 3.2 months, was effective in 66% of the patients (difference not significant). When the duration of therapy at each crossover period was compared, the percentage of patients who continued to take encainide was consistently higher than the percentage who continued to take quinidine (p less than 0.01). Twenty-nine percent of the patients discontinued encainide treatment, 23% because of clinical inefficacy and 6% because of adverse effects. Fifty-nine percent of the patients discontinued quinidine treatment, 20% because of inefficacy and 39% because of adverse effects. Based on antiarrhythmic efficacy, encainide is at least as effective as quinidine in the treatment of patients with supraventricular tachyarrhythmias. However, because of encainide's much greater tolerability, it was distinctly superior in terms of clinical use. This study was an open-design, randomized crossover trial to compare the efficacy and tolerability of encainide with those of quinidine in the treatment of supraventricular tachyarrhythmias.
