Pace mapping of postinfarction scar to detect ventricular tachycardia exit sites and zones of slow conduction.

INTRODUCTION: The exit site and central common pathway of slow conduction are preferred sites to guide radiofrequency ablation of postinfarction ventricular tachycardia (VT). Both require inducibility of VT. In addition, their low amplitude hampers direct recording of potentials generated by activation in pathways of slow conduction. We hypothesized that pace mapping during sinus rhythm would help to detect the VT exit site and potentials generated by activation in pathways of slow activation. METHODS AND RESULTS: In 13 patients suffering from VT late after anterior (n = 10) or inferior (n = 3) myocardial infarction, stimulation was performed in scarred endocardium at 23.5 (range 13 to 36) sites per patient during arrhythmia surgery. Multielectrode recordings (64 sites) during stimulation at a fixed cycle length of 500 msec were obtained. Endocardial breakthrough sites distant (>2 cm) from the pacing site were found at 4.3 (range 3 to 19) pacing sites per patient. Low-amplitude discrete potentials (LADPs) could be detected between the pacing site and the breakthrough site in 2.3 (range 0 to 13) of 4.3 stimulation sequences. In these patients, 19 VTs were induced and the exit site determined. In 6 patients, the distant pacing breakthrough site was identical to the VT exit site; in 7 patients, no similar exit sites were found. LADPs during VT were found at a median 2.0 (range 0 to 14) sites per patient. CONCLUSION: Pace mapping of the postinfarction endocardial scar during sinus rhythm revealed 50% of the endocardial exit sites of VT and the same number of LADPs observed during VT.

Results of maze surgery for lone paroxysmal atrial fibrillation.

BACKGROUND: If drug refractoriness to paroxysmal atrial fibrillation (PAF) occurs, arrhythmia surgery that involves channelling and the exclusion of specific atrial areas can abolish atrial fibrillation. The purpose of this study was to establish the effectiveness and safety of maze III surgery to abolish PAF. METHODS AND RESULTS: Surgery was performed in 41 selected patients who had long-standing, symptomatic, drug-refractory, lone PAF. At discharge, 35 patients (85%) were arrhythmia free, and 6 patients (15%) showed PAF and paroxysmal atrial tachycardia. Death or stroke did not occur during a mean follow-up of 31+/-16 months. At the end of follow-up, 39 patients (95%) had no PAF; however, in 2 patients (5%), PAF persisted and eventually required His bundle ablation and pacing. Three months after surgery, nodal escape rhythm was observed in only 1 patient, whereas sick-sinus syndrome emerged late after surgery in 2 patients. Antiarrhythmic drugs were used in 20% of patients during follow-up. The quality of life improved markedly after surgery and remained unchanged afterward. Echocardiographic findings did not alter, but exercise capacity increased. CONCLUSIONS: This pilot study demonstrates the effectiveness and safety of maze III surgery for lone PAF. In patients without sick-sinus syndrome, this intervention offers a sensible alternative to His bundle ablation and lifelong pacemaker dependency.

Triple sequential grafts using the internal mammary artery. An angiographic and short-term follow-up study.

Between December 1984 and December 1988, coronary artery bypass operations, involving the use of 119 sequential internal mammary artery grafts with three or more anastomoses per conduit, were performed in 116 patients. Patients included 14 women and 102 men, with a mean age of 60 years. They received a total of 629 anastomoses; 373 anastomoses were used in multiple sequential arterial bypass grafts; 116 sequential left and three right internal mammary artery jump grafts were performed. There were 27 patients with bilateral internal mammary artery grafts, but only 17 had completely arterial revascularizations. Perioperative infarction occurred in 3.4% of the patients; 1.7% of infarctions were related to sequential internal mammary artery grafts. There were no hospital deaths. Control angiography was performed within a month of the operation in 72 patients (with 371 anastomoses, of which 229 were in sequential arterial bypass grafts). The overall patency rate was 94.6%, and for the internal mammary artery sequential graft with three or more anastomoses it was 96.1%. The mean follow-up period was 13 months; 110 patients were in New York Heart Association class I; there was one non-cardiac-related death, and three patients (2.6%) had a late myocardial infarction. One was related to the area revascularized by the sequential internal mammary artery graft. Multiple sequential internal mammary artery bypass grafts in coronary artery disease are feasible, with a high short-term patency and a low perioperative morbidity and mortality.

Effectiveness of sotalol in preventing supraventricular tachyarrhythmias shortly after coronary artery bypass grafting.

To investigate the effectiveness and safety of low-dose sotalol (a class III antiarrhythmic beta-blocking agent) in the prevention of supraventricular tachyarrhythmias (SVTs) and to identify predictors for the occurrence of these arrhythmias shortly after coronary artery bypass grafting, 300 consecutive patients were randomized in a double-blind, placebo-controlled fashion. Patients with severely depressed left ventricular function or other contraindications for beta blockers were excluded. Beginning at 4 hours and up to the sixth day after surgery, 150 patients received 40 mg of sotalol every 6 hours. SVT was observed in 24 (16%) of 150 low-dose sotalol-and in 49 (33%) of 150 placebo-treated patients [p less than 0.005]. In patients receiving sotalol, atrial fibrillation was the only noted tachyarrhythmia, whereas in the placebo group, 42 (28%) patients had atrial fibrillation, 3 (2%) atrial flutter, 1 (0.7%) atrial tachycardia and 3 (2%) sinus tachycardia. Drug-related adverse effects necessitating discontinuation of the drug were noted in only 2 (1%) sotalol-treated patients and 4 (3%) placebo-treated patients (p = not significant). For both groups, univariate analysis indicated that older age, 1- or 2-vessel coronary artery disease, long bypass (greater than or equal to 150 minutes) and aorta cross-clamp time (greater than or equal to 120 minutes) were predictive variables for the occurrence of SVTs. Multivariate analysis showed that male sex (odds ratio 2.3), 1- or 2-vessel coronary artery disease (odds ratio 2.0) and older age (odds ratio 1.1) were independent risk factors for increased occurrence of postoperative SVT.(ABSTRACT TRUNCATED AT 250 WORDS)

Efficacy and safety of low- and high-dose sotalol versus propranolol in the prevention of supraventricular tachyarrhythmias early after coronary artery bypass operations.

Supraventricular tachyarrhythmias are reported in up to 40% of patients early after coronary artery bypass graft operations. In a randomized study, we compared the efficacy and safety of the class III antiarrhythmic beta-blocking drug sotalol versus propranolol at low and high doses in the prevention of supraventricular tachyarrhythmias in 429 consecutive patients after coronary artery bypass graft operations. Patients with severely depressed left ventricular function and other contraindications for beta-blockers were excluded. From the fourth hour up to the sixth day after coronary artery bypass, 74 patients received low-dose sotalol (40 mg every 8 hours), 66 patients low-dose propranolol (10 mg every 6 hours), 133 patients high-dose sotalol (80 mg every 8 hours), and 156 patients high-dose propranolol (20 mg every 6 hours). Baseline characteristics were comparable in all groups. Supraventricular tachyarrhythmia was observed in 10 of 72 (13.9%) who received low-dose sotalol, 12 of 64 (18.8%) who received low-dose propranolol, 13 of 119 (10.9%) who received high-dose sotalol, and 19 of 139 (13.7%) who received high-dose propranolol (not significant). Drug-related adverse effects necessitating discontinuation of the drug occurred in four receiving low doses (2.9%) and in 31 receiving high doses (10.7%) (p less than 0.02). In conclusion, no medication was found to be superior, although supraventricular tachyarrhythmias tended to be less prevalent in patients treated with sotalol than in those treated with propranolol. Moreover, significantly fewer adverse effects were noted in both low-dose groups. Therefore, low-dose beta-blocking treatment, especially low-dose sotalol, seems preferable.

[Predictive characteristics for early mortality in patients on the waiting list for aortocoronary bypass surgery]. / Voorspellende kenmerken voor vroege sterfte bij patiënten op de wachtlijst voor aorto-coronaire bypass-chirurgie.

In 1986, 1124 patients were selected for coronary artery bypass surgery (CABG). Of patients in line for CABG 25 (2.2%) died of a cardiac cause before operation. This complies with a cardiac mortality risk of 8.3 patients per 100 patient years follow-up. To assess patient characteristics predictive for early mortality before surgery, 25 deceased patients were analysed and compared with 50 controls matched by age, gender, type of surgery and priority. Using multivariate analysis, cardiac enlargement on chest X-ray, positive exercise testing with short duration (less than 6 minutes), smoking, coumarin treatment, unstable angina just prior to angiography and left main or three-vessel disease were independent predictors for death while waiting for CABG. We conclude that patients with the above mentioned characteristics have an increased short term mortality while waiting for CABG. These indicators may contribute important information for determination of priority in patients at high risk while waiting for CABG.

Left ventricular segmental wall motion score as a criterion for selecting patients for direct surgery in the treatment of postinfarction ventricular tachycardia.

No indisputable criteria for selecting candidates for direct surgery in postinfarction ventricular tachycardia are yet available. We prospectively tested the result of surgery in patients showing normokinesia or slight hypokinesia in at least 3 of 9 segments of the left ventricle as determined on two oblique projections of the left ventricular angiogram. Sixty consecutive patients with recurrent symptomatic ventricular tachycardia were stratified on the basis of this criterion; 50 candidates were thus eligible for surgery. Direct surgery (endocardial resection and/or cryoablation) was performed in 23 patients (after a mean of 4.1 antiarrhythmic drug trials), while 27 patients were maintained on drug treatment (at discharge, a mean of 3.7 drug trials). Surgery was map-guided in 19 patients and non-map-guided in four emergency cases. No patients died in the immediate postoperative phase, but two (9%) died during follow-up. The actuarial survival at 12 months was 93%; the surgery-alone cure rate for ventricular tachycardia was 78%. Of the 27 non-operated surgical candidates, two died during in-hospital drug testing and five after discharge (total 26%). Actuarial survival at 12 months was 78% and did not differ significantly from that of the operated patients. After discharge, 80% of the non-operated surgical candidates still using the drug at discharge remained free of recurrence. In the 10 drug-treated non-surgical candidates (at discharge, a mean of 3.8 drug trials), survival and the number of arrhythmia-free patients were markedly lower than in surgical candidates. This study shows that the segmental wall motion score is of great clinical value and can be applied for stratification of patients with ventricular tachycardia after myocardial infarction for either surgery or medical therapy.

Is chronic atrial stimulation a reliable method for single chamber pacing in sick sinus syndrome?

To evaluate the feasibility of chronic atrial pacing (AAI) in sick sinus syndrome (SSS), 22 patients (pts) with bradytachycardia syndrome (BTS) and 17 patients with only bradyarrhythmias (BA) were studied on the incidence of supraventricular tachycardias (SVT) and occurring AV block. A scoring system based on symptoms of SVT was developed (grade 0-5). All patients had proven normal AV conduction before PM implantation. In the BTS-group, nine patients (41%) had symptomatic SVT at the end of follow-up (mean 53 months), despite drug therapy. These patients had a high SVT score on entry (mean 3.2). High degree AV block occurred in three patients. Although in the BA-group SVT arose in six patients (35%), there was only one symptomatic patient at the end of follow-up (mean 36 months). In this group, only one patient developed high degree AV block. Atrial stimulation should be considered as a reliable therapy in patients with SSS and low SVT score before PM implantation when normal AV conduction is present.