Encircling endocardial ventriculotomy for refractory ischemic ventricular tachycardia

A history of collaboration between electrophysiologists and arrhythmia surgeons

Introduction: The notion that medically‐refractory arrhythmias might one day be amenable to interventional therapy slowly began to appear in the early 1960's. At that time, there were no “interventional electrophysiologists” or “arrhythmia surgeons” and there was little appreciation of the relationship between anatomy and electrophysiology outside the heart's specialized conduction system. Methods: In this review, we describe the evolution of collaboration between electrophysiologists and surgeons. Results: Although accessory atrio‐ventricular (AV) connections were first identified in 1893 and the Wolff‐Parkinson‐White (WPW) syndrome was described 37 years later (1930), it was another 37 years (1967) before those anatomic AV connections were proven to be responsible for the clinical syndrome. The success of the subsequent surgical procedures for the WPW syndrome, AV node reentry tachycardia, automatic atrial tachycardias, ischemic and non‐ischemic ventricular tachycardias and atrial fibrillation over the next two decades depended on a close, sometimes daily, collaboration between electrophysiologists and surgeons. In the past two decades, that tight collaboration was largely abandoned until the recent introduction of “hybrid procedures” for the treatment of atrial fibrillation. Conclusions: A retrospective assessment of the 50 years of interventional therapy for arrhythmias clearly demonstrates the clinical benefits of a close collaboration between electrophysiologists and arrhythmia surgeons, regardless of which one is actually performing the intervention.

Estudo comparativo da evolução e sobrevida de pacientes com claudicação intermitente, com ou sem limitação para exercícios, acompanhados em ambulatório específico

CONTEXTO: Os fatores de risco para doença aterosclerótica, que influenciam na evolução natural dessa doença, estão bem estabelecidos, assim como o benefício do programa de exercícios para pacientes claudicantes. Entretanto, faltam informações sobre a relação entres limitações clínicas e fatores de risco, com desempenho do programa de caminhadas e suas implicações na evolução e mortalidade destes pacientes. OBJETIVO: Comparar, ao longo do tempo, a distância de claudicação e sobrevida de pacientes claudicantes em ambulatório específico, com ou sem limitação para exercícios. MÉTODOS: Foi feito um estudo tipo coorte retrospectivo de 185 pacientes e 469 retornos correspondentes, no período de 1999 a 2005, avaliando-se dados demográficos, distância média de claudicação (CI) e óbito. Os dados foram analisados nos programas Epi Info, versão 3.2, e SAS, versão 8.2. RESULTADOS: A idade média foi de 60,9±11,1 anos, sendo 61,1% do sexo masculino e 38,9% do sexo feminino. Oitenta e sete por cento eram brancos, e 13%, não-brancos. Os fatores de risco associados foram: hipertensão (69,7%), tabagismo (44,3%), dislipidemia (32,4%) e diabetes (28,6%). Nos claudicantes para menos de 500 m, a CI inicial em esteira foi de 154,0±107,6 m, e a CI final, de 199,8±120,5 m. Cerca de 45% dos pacientes tinham alguma limitação clínica para realizar o programa de exercícios preconizado, como: angina (26,0%), acidente vascular cerebral (4,3%), artropatia (3,8%), amputação menor ou maior com prótese (2,1%) ou doença pulmonar obstrutiva crônica (1,6%). Cerca de 11,4% dos pacientes tinham infarto do miocárdio prévio, e 5,4% deles usavam cardiotônico. O tempo de seguimento médio foi de 16,0±14,4 meses. A distância média de CI referida pelos pacientes aumentou 100% (de 418,47 m para 817,74 m) ao longo de 2 anos, nos grupos não-limitante (p < 0,001) e não-tabagista (p < 0,001). A sobrevida dos claudicantes foi significativamente menor no grupo com limitação. A análise de regressão logística mostrou que a limitação para realização de exercícios, isoladamente, influenciou significativamente na mortalidade (p < 0,001). CONCLUSÃO: A realização correta e regular dos exercícios e o abandono do fumo melhoram a distância de claudicação, além de reduzir a mortalidade nesses casos, seja por meio de efeitos positivos próprios do exercício, seja por meio de controle dos fatores de risco e de seus efeitos adversos.

Reflections on definitive surgical treatment of postinfarction ventricular tachycardia

The past 15 years have witnessed a substantial commitment to the understanding and surgical cure of postinfarction ventricular tachycardia, and the results of treatment have steadily improved. However, outside influences have had a negative impact on the use of this modality. With the widespread availability of implantable defibrillators, this has become an attractive alternative therapy to the sometimes difficult definitive surgical treatment. Meanwhile, early thrombolytic therapy for the management of evolving myocardial infarctions has been found to create a postinfarction electrical substrate that does not appear to be arrhythmogenic. As a result, clinical efforts to develop and refine definitive ventricular tachycardia surgical treatments have all but ceased. The intent of this article is to review the events that took place in this apparently transient era.

Encircling endocardial ventriculotomy for malignant ventricular arrhythmias. Effect on cardiac performance

Cardiac performance and hemodynamics were studied with radionuclide ventriculography in 19 survivors of aneurysmectomy and encircling endocardial ventriculotomy for recurrent, sustained ventricular arrhythmia (group I). To characterize the effect of the ventriculotomy on cardiac function, comparisons were made with a similar group of patients who underwent aneurysm surgery for angina pectoris and/or congestive heart failure (group II). Functional classification revealed no difference between the groups and they achieved the same level of exercise after surgery. No intergroup difference was found postoperatively with respect to right or left ventricular ejection fraction, regional ejection fractions, peak ejection rate, cardiac index or stroke volume. Peak filling rate was also similar, as were cardiac volumes. Exercise did not change any parameter of this intergroup similarity. The authors conclude that most patients with moderately impaired left ventricular function who undergo left ventricular aneurysmectomy with encircling endocardial ventriculotomy do not differ in postoperative hemodynamics and systolic or diastolic function from those treated with simple aneurysmectomy.

Current status of surgery for ventricular tachyarrhythmias

This article outlines the accepted histopathologic and electrophysiologic theories underlying the etiology of medically refractory ventricular tachyarrhythmias. It delineates the indications and techniques for the electrophysiologic study of the ventricle. Finally, the surgical procedures available as well as their indications and results are elucidated.

Recurrent ventricular tachycardia: how effective is surgical management?

Previous "blind" surgical intervention for recurrent, sustained ventricular tachycardia has been disappointing. Successful surgical intervention requires that a local arrhythmia circuit be interrupted, ablated, or disengaged from the adjacent healthy myocardium while incurring minimal injury to the remaining functional heart. Evidence is accumulating in both animals and human beings that myocardial ischemic damage may yield all the requisite substrates for a sustained reentrant ventricular arrhythmia. Ninety consecutive patients with recurrent, sustained ventricular tachycardia which was refractory to medical therapy underwent electrophysiologically directed surgical therapy. There were eight operative deaths (9 percent surgical mortality within 30 days after operation). In 65 of the 80 patients who underwent postoperative electrophysiologic studies, programmed ventricular stimulation was unable to replicate the clinical arrhythmia. Eight of the 17 patients with postoperatively inducible tachycardia were successfully treated with drugs.

When is myocardial mapping clinically valuable?

All cardiac arrhythmias are either automatic or reentrant. Automatic arrhythmias occur in the periinfarction or perioperative period. Chronic, recurrent arrhythmias are typically reentrant. By definition, reentrant arrhythmias are inducible with programmed electrical stimulation. When a malignant cardiac arrhythmia is identified, the patient is taken to the electrophysiologic laboratory for study. Reentrant ventricular tachyarrhythmias are induced with programmed electrical stimulation. Pharmacologic suppression is guided by electrophysiologic testing. When antiarrhythmic suppression fails, surgical intervention may be an effective alternative. Endocardial catheter mapping before surgery may serve as an important guide to the surgeon. Myocardial mapping is clinically valuable only when all antiarrhythmic therapy has failed, and the patient is considered to be a candidate for surgical intervention. When surgical intervention is planned, we consider preoperative catheter mapping desirable and intraoperative electrophysiologic localization mandatory.