Surgical removal of entrapped endocardial leads without using extracorporeal circulation

Of 267 patients having a tined endocardial lead implanted from 1978 to December 1983, three (1.1%) developed pulse generator pocket infection. Proper treatment of this complication involves removal of the pulse generator, continued external pacing via the implanted lead, pocket drainage and administration of specific antibiotics until the infected area clears. In two patients, the electrode could not be removed by traction. A sternotomy was performed, the pericardium was opened, the endocardial electrode was located by palpation, and a purse string suture (PSS) was prepared around it on the right ventricular wall. A new myocardial electrode with its corresponding generator was then implanted to reestablish pacing. Through the PSS the myocardium was incised, the distal end of the endocardial lead was exteriorized and severed, and the PSS was tied. The remaining lead was withdrawn proximally and the surgical wounds were closed. The results of this procedure have been been excellent, allowing the removal of the entrapped leads, with continuous pacing and without the need for extracorporeal circulation.

Laser photoablation of pathological endocardium: in vitro findings suggesting a new approach to the surgical treatment of refractory arrhythmias and restrictive cardiomyopathy

In selected patients, malignant ventricular tachyarrhythmias have been successfully abolished by excision of subendocardial arrhythmogenic foci. Likewise, in certain patients in whom restrictive cardiomyopathy is due to endocardial thickening, endocardial resection has resulted in hemodynamic improvement. The present study was designed to explore the utility, in vitro, of laser photoablation of pathologically thickened endocardium. Endocardial photoablation was easily accomplished regardless of etiological or anatomical variations using either the focused beam of a carbon dioxide laser or argon laser light delivered through a 200-microns optical fiber. Photoablation of areas as large as 3.9 X 1.3 cm was performed within 40 seconds. The extent or depth of endocardial photoablation could be limited to 2 mm2 in area or 1 mm in depth using either form of laser therapy. These in vitro results suggest that either carbon dioxide or argon laser phototherapy can be successfully applied to the surgical treatment of refractory arrhythmias and restrictive cardiomyopathy. Advantages of laser photoablation include speed and precision. Furthermore, laser photoablation obviates the difficulty associated with conventional techniques in establishing tissue planes.

The status of surgery for cardiac arrhythmias

Successful surgical treatment of all forms of supraventricular tachyarrhythmias is dependent on accurate electrophysiologic guidance. Surgery for WPW syndrome is no longer experimental and should be offered to (1) patients with medically refractory reciprocating tachycardia associated with the syndrome, (2) patients with spontaneous atrial fibrillation who are at risk for sudden death, (3) patients with drug intolerance, and (4) young, otherwise healthy patients with symptoms that warrant more than minimal medical therapy. The current results of surgery for WPW syndrome would seem to lessen the likelihood that a major new method of superior nonpharmacologic treatment will emerge in the near future. Surgery for most other types of supraventricular tachyarrhythmias remains experimental and should be applied only under the most controlled circumstances and after satisfying the most rigid criteria for surgical intervention, the main indication being absolute medical refractoriness. The single exception at the present time is surgery for AV node reentry tachycardia, which appears to be easily cured by the new technique of discrete cryosurgery of the peri-AV nodal region of the lower right atrial septum. In a majority of patients, ventricular tachycardia can be successfully ablated surgically without the use of electrophysiologic mapping to guide the surgeon. If such an approach is taken, however, the surgical treatment of these complex arrhythmias becomes a completely service-oriented exercise. Although delivery of such a service is of undeniable importance, the potential for learning more about these complex and lethal arrhythmias is lost unless each patient is studied as comprehensively as possible.(ABSTRACT TRUNCATED AT 250 WORDS)

Encircling endocardial incision interrupts efferent vagal-induced prolongation of endocardial and epicardial refractoriness in the dog

The purpose of this study was to test the hypothesis that vagal efferent nerves travel in the left ventricular subendocardium in a base to apex direction. Efferent vagal stimulation during constant background isoproterenol infusion prolonged left ventricular endocardial and epicardial effective refractory periods in a control state and after a left ventriculotomy performed while dogs were supported by cardiopulmonary bypass. After a 2 mm deep endocardial circumferential incision, efferent vagal stimulation still prolonged the effective refractory period at an endocardial site basal to the encircling endocardial incision, but no longer prolonged the effective refractory period at the endocardium or immediately overlying epicardium apical to the incision. Interpretation of these data suggests that efferent vagal fibers travel in the superficial subendocardium of the canine left ventricle in a base to apex direction, penetrating upward to innervate the epicardium. Conceivably, a lesion such as a subendocardial myocardial infarction could selectively interrupt efferent vagal innervation, leaving sympathetic innervation unopposed. This may be a source of some arrhythmias.

Encircling endocardial resection with complete removal of endocardial scar without intraoperative mapping for the ablation of drug-resistant ventricular tachycardia

Encircling endocardial resection, with complete removal of endocardial scar unguided by intraoperative mapping, was employed in 10 patients with drug-resistant sustained ventricular tachycardia. Reproducible sustained ventricular tachycardia was induced in all patients preoperatively with programmed electrical stimulation. A trial of conventional antiarrhythmics had failed in all 10 patients; seven patients required frequent cardioversion, and three patients required overdrive suppression with temporary transvenous pacing. Encircling endocardial resection was performed in all patients, with complete removal of endocardial scar; partial reimplantation of the mitral apparatus was required in nine patients. Eight patients underwent aneurysmectomy, and the nine patients who required concomitant aorta-coronary bypass received a total of 13 grafts (mean 1.3 grafts per patient). There were no spontaneous postoperative arrhythmias. One patient without postoperative clinical arrhythmias, who had required daily preoperative cardioversion, had inducible ventricular tachycardia with postoperative programmed electrical stimulation, but not after loading with procainamide. Mean follow-up was 17.3 months. Eight patients are alive and well. There were two late deaths. One patient died with recurrent ventricular septal defects 2.5 months following extensive septal encircling endocardial resection, and one patient was readmitted after 4 months with massive pulmonary embolus and right-sided heart failure. This early experience suggests that this procedure, with complete removal of endocardial scar, successfully ablates reentrant ventricular tachycardia. We believe that the procedure will prove to be more effective than localized endocardial resection because the encircling procedure removes all ventricular sites that have the potential to generate reentrant ventricular tachycardia.

[The course of endomyocardial fibrosis following surgical endocardial decortication]

Between 1971 and 1983 the authors observed 10 patients with left ventricular (n = 3) and biventricular (n = 7) endomyocardial fibrosis (7 women and 3 men). Seven of the 10 patients underwent open heart surgery with endocardial decortication of the left (n = 5) or left and right (n = 2) ventricle combined with mitral (n = 6) and tricuspid (n = 2) valve replacement. In 1 patient left ventricular endocardial decortication was performed without valve replacement. Three of the 10 patients were treated medically because functional limitation was only mild. One of the medically treated patients died 4 years later from congestive heart failure. Postoperative follow-up was 4.4 years. Two of the 7 patients who had undergone surgery died due to recurrence of endomyocardial fibrosis with blood eosinophilia of 46% (Löffler's endocarditis) in one, and due to severe left ventricular heart failure in the other. Annual mortality was 6.4%. NYHA classification was 3.4 pre- and 2.0 (p less than 0.005) postoperatively. Four patients were recatheterized 10 months after surgery: left ventricular end-diastolic pressure had decreased significantly from 24.6 to 13.6 mm Hg, cardiac index had increased slightly from 1.9 to 2.4 l/min/m2, left ventricular end-diastolic volume had increased from 69 to 84 ml/m2 (ns) and left ventricular ejection fraction remained unchanged pre- and postoperatively (59% and 57% respectively). It is concluded that endomyocardial fibrosis involves both ventricles in 70% of all patients, and that women are affected more frequently than men. Endocardial decortication with AV-valve replacement is regarded as the therapy of choice.(ABSTRACT TRUNCATED AT 250 WORDS)

Surgical management of ventricular tachycardia

Surgical techniques that are used to treat VT have evolved into a sophisticated science over the past decade. Combining advanced electrophysiologic stimulation and study of the heart with innovative surgical approaches has been the key to successfully managing patients with recurrent VT. Several different surgical approaches have been developed. Endocardial excision and aneurysmectomy, which are combined with preoperative and intraoperative mapping, are the procedures currently used at HUP. Other institutions use simple ventriculotomy, endocardial encircling ventriculotomy, cryosurgery, and pacemaker therapy. The ability to successfully terminate VT has improved markedly from early attempts with use of these techniques. Long-term efficacy of these procedures and possible late complications remain to be established. Nursing management of the patient who undergoes surgery for VT is a challenging experience. It requires knowing basic principles of caring for the patient who will have open heart surgery. It also requires in-depth understanding of new and changing techniques and procedures to provide knowledgeable care to the patient.

Staphylococcal abscess complicating endocardial aneurysmectomy

Subendocardial left ventricular aneurysmectomy relieved previously intractable ventricular tachycardia in a 68-year-old man with severe coronary artery disease. Staphylococcal septicemia developed postoperatively; an infected venoclysis site may have provided the portal of entry. Autopsy confirmed staphylococcal abscess at the epicardial aspect of the ventriculotomy, constituting the first reported case, to our knowledge, of this complication following endocardial surgery.

Subendocardial resection for ventricular tachycardia: predictors of surgical success

We retrospectively evaluated the first 100 patients who underwent mapping-guided subendocardial resection (SER) at our hospital for drug-refractory sustained ventricular tachycardia caused by coronary artery disease. There were 91 survivors of surgery with 200 morphologically distinct types of ventricular tachycardia. Eighty-three patients (91%) were cured of ventricular tachycardia by SER alone (60 patients or 66%) or by SER in combination with antiarrhythmic drug therapy (23 patients or 25%) (mean follow-up, 28 +/- 19 months). There were four late sudden deaths and four patients continued to have rare episodes of spontaneous ventricular tachycardia after surgery despite receiving antiarrhythmic drugs. Factors associated with failure of SER alone to cure ventricular tachycardia were presence of disparate sites of ventricular tachycardia origin (greater than 5 cm between mapped sites of origin; 64% vs 30% failure rate) and presence of multiple morphologically distinct spontaneous tachycardias (47% vs 25% failure rate). A log-linear model of multivariate analysis identified disparate sites of origin of ventricular tachycardia and the absence of a discrete left ventricular aneurysm as the only independent variables associated with failure of surgery alone. Inferior wall site of origin (41% vs 12% failure) and right bundle branch block morphology of ventricular tachycardia (20% vs 7% failure) were also significantly associated with failure of surgery to cure ventricular tachycardia. Mapping-guided SER is a highly effective mode of treatment for drug-refractory ventricular tachycardia, despite the existence of subgroups of patients with higher-than-average surgical failure rates.

Body surface late potentials: effects of endocardial resection in patients with ventricular tachycardia

We studied 37 patients undergoing endocardial resection for medically refractory ventricular tachycardia (VT). Each was studied before and after surgery by programmed ventricular stimulation and signal-averaged electrocardiography. Low-amplitude late potentials were identified preoperatively in 76% of patients. In the 24 patients without postoperative VT the effect of surgery was to shorten the filtered QRS duration (137 +/- 27 to 121 +/- 26 msec; p = .003), increase the voltage in the last 40 msec of the filtered QRS (16.5 +/- 16.1 to 39.0 +/- 29.4 microV; p = .003), and decrease the incidence of late potentials (71% to 33%; p = .03). The filtered QRS complex was unchanged in 13 patients whose VT persisted after surgery. No preoperative variable predicted which patients would not have inducible VT after surgery. However, loss of a late potential after surgery in nine of 10 patients was associated with absence of inducible VT (p less than .02). Loss of a late potential was not necessary for surgical success. Eight of 18 patients with a persistent late potential did not have inducible VT. The signal-averaged electrocardiogram predicted a successful outcome after endocardial resection if the late potential was no longer present.

Operative therapy for ventricular arrhythmia

The history of surgical attempts to control ventricular arrhythmia is reviewed and current methodology is presented in detail. The results of the various surgical approaches and future trends in the management of this troublesome condition are discussed.

Evaluation of arrhythmogenicity of surgically induced endocardial versus ischemic myocardial damage

Ventricular tachyarrhythmias are common sequelae of ischemic myocardial damage. To assess the susceptibility to sustained ventricular tachycardia in a canine model in which endocardial excision was performed, 30 adult mongrel dogs were divided into three groups and studied in an open-chest condition, anesthetized under pentobarbital anesthesia, 7 to 14 days after undergoing one of three alternative procedures: (Group A) sham-operated controls, 10 dogs; (Group B) left ventricular endocardial excision, 10 dogs; and (Group C) myocardial infarction produced by a 2-hour occlusion and subsequent reperfusion of the left anterior descending coronary artery, 10 dogs. Using programmed ventricular pacing with two extrastimuli via plunge electrodes at 10 normal sites in the distribution of the left anterior descending coronary artery in each dog, sustained ventricular tachycardia was induced in 0/10 Group A dogs at 0/100 sites and in 0/10 Group B dogs at 0/100 sites; in contrast, in Group C, 7/10 (70%, p less than 0.01) dogs had inducible sustained ventricular tachycardia and at 39/70 (56%, p less than 0.001) sites. Thus, 7 to 14 days following endocardial excision, dogs are no more susceptible to the initiation of sustained ventricular tachycardia than are sham-operated control animals. This is in contrast to dogs with chronic heterogeneous infarctions (Group C) due to coronary occlusion and reperfusion, which are highly susceptible to ventricular tachycardia initiation.

Surgical treatment of ventricular tachycardias. Complete versus partial encircling endocardial ventriculotomy

Forty consecutive patients underwent electrophysiologically guided encircling endocardial ventriculotomy as treatment for recurrent sustained ventricular tachycardia resulting from coronary artery disease and previous myocardial infarction. Twelve patients (30%, Group I) had a complete encircling endocardial ventriculotomy and 28 (70%, Group II) had a partial encircling endocardial ventriculotomy (54.4% +/- 2.2% of the left ventricular endocardial circumference) at the earliest electrical activation during ventricular tachycardia. There were no significant differences between the two groups in age, sex ratio, New York Heart Association class, coronary disease, aneurysm location, concomitant bypass grafting, and left ventricular function. One patient of Group I and two patients of Group II did not survive the perioperative period (8% versus 7%, not significant). The survivors were restudied electrophysiologically about 3 weeks after the operation. Eight patients of Group I and 19 patients of Group II were free of ventricular tachycardia (no spontaneous or inducible ventricular tachycardia) without antiarrhythmic drugs (73% versus 73%, not significant). The mean follow-up period in Group I is 22.6 months and in Group II, 15.2 months. Five patients of Group I and of Group II developed severe left ventricular dysfunction (46% versus 8%; p = 0.025). Also, congestive heart failure was a significant cause of death in Group I patients (p = 0.036). In conclusion, electrophysiologically guided partial encircling endocardial ventriculotomy is highly efficient as a surgical treatment of recurrent sustained ventricular tachycardia. Complete encircling endocardial ventriculotomy offers no better ablation of arrhythmias and should be avoided because of its apparent hazards to left ventricular performance.

Results of electrophysiologically guided operations for drug-resistant recurrent ventricular tachycardia and ventricular fibrillation due to coronary artery disease

Over a 39 month period, 143 patients with coronary artery disease had programmed stimulation (PES) for recurrent ventricular tachycardia (VT) or ventricular fibrillation (VF). Twenty-two patients underwent operations. Ages ranged from 40 to 71 years; 20 of the 22 were men. All patients had coronary artery disease and 11 had left ventricular aneurysms. The mean ejection fraction was 31% (16% to 50%). Eighteen of the 22 patients underwent operations for drug-resistant ventricular arrhythmias (more than six different drugs plus drug combinations tested per patient). Nineteen patients had intraoperative mapping, endocardial resection, and/or an encircling endocardial ventriculotomy. Three patients with ischemia-related VT had coronary artery bypass (CABG) alone. The 30 day operative mortality was 14%. Thirteen of 19 (68%) operative survivors were effectively controlled with operation alone or a combination of operation and previously ineffective drug therapy. Of the six patients whose VT was inducible postoperatively, three have experienced episodes of sustained VT and one patient died suddenly. Three of these patients have the automatic implantable defibrillator. Operation guided by endocardial mapping is effective alone or in combination with drugs in this select group of patients. If the patients' VT was uninducible postoperatively with or without the addition of antiarrhythmic therapy, late deaths (3/19) were due to poor myocardial reserve and coronary artery disease, not the reemergence of sustained ventricular arrhythmias during a mean follow-up of 15 months.

Difficulty of extraction of chronically implanted tined ventricular endocardial leads

The dislodgment rate of permanent pacing ventricular and atrial endocardial leads has significantly decreased with the incorporation of tines as a fixation device. In contrast, transvenous manual extraction of chronically implanted endocardial leads is, at times, clinically indicated, particularly when pacemaker system infection is present. The success rate of such extraction attempts for ventricular endocardial leads over the past 5 years was reviewed. Extraction was usually successful (six of seven attempts) in patients with silicone rubber nontined (or short-tined) older ventricular endocardial leads (Group A). However, in patients with newer urethane long-tined ventricular endocardial leads (Group B), extraction was unsuccessful in three of four attempts. Because of entrapment of the distal electrode tip in the right ventricular apex, manual traction of these leads resulted in permanent conductor material stretching with resultant urethane insulator material breakage in the region of the joints with proximal and distal electrodes. The one successful extraction in Group B was technically difficult and appeared to create a significant risk of intracardiac lead separation. This experience indicates that with improved pacemaker lead design decreased lead dislodgment has been obtained at the cost of increased difficulty of ventricular endocardial lead extraction. Such difficulty should be anticipated when a clinical decision is made to attempt to extract the new urethane long-tined ventricular leads.

Encircling endocardial resection for sustained drug-resistant ventricular tachycardia

Localized endocardial resection guided by intraoperative mapping has been used recently to manage patients with drug-resistant ventricular tachycardia. Although not uniformly successful, this procedure is superior to simple aneurysmectomy. This report describes the authors' early experience with encircling endocardial resection with complete removal of endocardial scar in seven patients with drug-resistant, sustained, ventricular tachycardia, as identified by electrophysiologic studies. Intraoperative mapping was not used. Although no spontaneous clinical arrhythmia occurred after operation, ventricular tachycardia could be induced in one patient, but not after loading with procainamide. This was the only patient who required long-term antiarrhythmic therapy. There were no operative deaths, but one patient died 21/2 months after endocardial resection with recurrent ventricular septal defects and another died after 4 months. Our early experience indicates that encircling endocardial resection effectively eliminates re-entrant ventricular tachycardia and identifies ventricular septal defect as a potential postoperative complication following extensive septal endocardial resection.

The treatment of malignant ventricular arrhythmias with combined endocardial resection and implantation of the automatic defibrillator: preliminary report

Fourteen patients with refractory ventricular tachyarrhythmias were treated with combined endocardial resection and implantation of the automatic defibrillator. There were 11 men and 3 women with a mean age of 53 years (range, 41 to 58 years). All patients had coronary artery disease; the mean ejection fraction was 26%, and the mean number of cardiac arrests was 2.6. Programmed electrical stimulation induced sustained ventricular tachycardia in 13 patients and nonsustained ventricular tachycardia in 1. Operative endocardial mapping in the 13 patients with sustained ventricular tachycardia demonstrated a septal focus of early activation in 9 patients and a nonseptal site in 4. Following resection, sustained ventricular tachycardia could not be reinduced. There was 1 operative death. Programmed electrical stimulation performed one month after operation induced ventricular tachycardia in 5 patients, but tachycardia could not be induced in the other 8 survivors. The longest follow-up was 32 months; the average was 17 months. There were 2 late deaths. One patient died of myocardial infarction and 1 of pulmonary edema following a routine cholecystectomy. In another patient, late ventricular tachycardia developed but was automatically terminated by the implanted defibrillator. These results suggest that endocardial resection combined with implantation of the automatic defibrillator may offer the greatest protection yet available to patients with malignant ventricular tachyarrhythmias.

ST segment elevation with ventricular aneurysm: results of encircling endocardial ventriculotomy

The ST segment elevation characteristic of ventricular aneurysm is thought to represent unmodified repolarization of the opposing wall or to arise from viable tissue at the border of the scar because of ischemia, traction or the non-uniform injury that is the architecture for ventricular tachycardia. Encircling endocardial ventriculotomy to prevent tachycardia interrupts coronary perfusion to the viable tissue bordering the scar, with noticeable loss of electrical and mechanical function. Five patients had anterior or apical aneurysms resected and encircled to treat recurrent ventricular tachycardia. ECGs were examined 49 days +/- 12 SEM post-operatively. Encircling did not eliminate their ST segment elevation. Only one patient had less ST elevation post-operatively. Thus ST elevation associated with aneurysms does not arise from viable tissue at the edge of the scar because it persists after this tissue is damaged by encircling endocardial ventriculotomy.

Fragmented endocardial electrical activity in patients with ventricular tachycardia: a new guide to surgical therapy

Eight patients with ventricular aneurysms and ventricular tachycardia refractory to drugs were studied. Each patient underwent intraoperative epicardial and endocardial mapping during stable sinus rhythm. After aneurysmectomy, areas of the endocardial border zone which demonstrated fragmented activity were excised. Mapping was then repeated to ensure that major areas of fragmentation did not remain. Mapping was completed in less than 20 minutes in each patient. One patient died of pump failure before hospital discharge and a second patient, who was arrhythmia-free, died of pump failure 12 months postoperatively. Six patients are alive and free of ventricular tachycardia 5 to 25 months (mean 11.5) postoperatively. We conclude that excision of areas of fragmented electrical activity in the endocardial border zone of ventricular aneurysms is a useful approach to surgical therapy for ventricular tachycardia. This approach allows an excision directed to arrhythmogenic areas without the need for tachycardia induction in the operating room.

Subendocardial resection for refractory ventricular tachycardia: effects on ambulatory electrocardiogram, programmed stimulation and ejection fraction, and relation to outcome

The inducibility of ventricular tachycardia by programmed stimulation was correlated with ventricular ectopic activity on ambulatory electrocardiogram, ejection fraction and clinical outcome in 36 patients after endocardial resection for medically refractory ventricular tachycardia. Ventricular tachycardia was noninducible postoperatively in 25 patients and was inducible in 11. After administration of antiarrhythmic drugs, ventricular tachycardia could no longer be induced in four patients and remained inducible in the other seven patients. All 36 patients had postoperative and 20 had preoperative ambulatory electrocardiograms obtained while they were not receiving drug therapy. Pre- and postoperative ambulatory electrocardiograms did not differ in mean hourly ventricular premature depolarization frequency, Lown arrhythmia grade or change in grade (pre- vs. postoperative). The majority of postoperative patients had repetitive forms of ventricular arrhythmia postoperatively and there was no difference between patients with inducible and noninducible ventricular tachycardia in regard to Holter monitoring characteristics. There was no significant difference in postoperative ejection fraction between patients with inducible and noninducible ventricular tachycardia postoperatively. Ventricular tachycardia has recurred in 2 of 29 patients who had no inducible tachycardia at the time of hospital discharge and were followed up for a mean of 1 year; it has recurred in one of seven patients in whom it was still inducible at the time of hospital discharge and who were followed up for a mean of 7 months.(ABSTRACT TRUNCATED AT 250 WORDS)

Surgical therapy for ventricular tachyarrhythmias

Recurrent sustained ventricular tachyarrhythmias unresponsive to medical therapy are associated with a one year mortality of 70 to 85 per cent. Patients who are susceptible to these re-entrant arrhythmias usually have a history of previous myocardial infarction or chronic myocardial ischemic disease. More specifically, these patients demonstrate both anatomic and electrophysiologic derangements. Experimental work suggests that regions of non-uniform damage render the ventricle most susceptible to ventricular tachyarrhythmias, and even relatively large areas of homogeneous myocardial ischemic damage may not display the same susceptibility to these arrhythmias. Surgical techniques are being devised to treat patients with ventricular tachyarrhythmias refractory to medical management. These have provided control of arrhythmias in patients whose disease was previously resistant to all medical treatment. The evolving surgical therapies presently employed share either of two physiopathologic consequences which render them successful: the homogeneous ablation of previous heterogeneous myocardial ischemic damage or the delimiting of an arrhythmogenic focus by excluding conduction to surrounding myocardium. Finally, antitachycardia and defibrillating devices have also been developed to facilitate the management of patients not controlled satisfactorily with either conventional or investigative drugs. The surgeon will need to be familiar with these devices as well.

Left endomyocardial fibrosis with severe mitral insufficiency; the case for mitral valve repair. A report of 4 cases

Left ventricular endomyocardial fibrosis accompanied by severe mitral insufficiency occurring in 4 adolescent African patients is reported. Mitral valve repair was successfully performed in all 4 cases including annuloplasty in 3 and chordal shortening in one. Short-term follow-up of up to 10 months indicated substantial clinical improvement and decrease of the cardiothoracic ratio in all. It is emphasized that mitral valve repair appears to be the method of choice in treating mitral incompetence in the localized form of endomyocardial fibrosis, where endocardiectomy is not required in the area of the papillary muscles.

Sustained ventricular tachyarrhythmias during the early postinfarction period: electrophysiologic findings and prognosis for survival

Forty patients with sustained tachycardia occurring 3 to 65 days after myocardial infarction underwent programmed ventricular stimulation within 3 months of the infarction. Patients were characterized clinically by a complicated initial 48 hours of hospitalization for their acute infarction (85% of study group). The development of bundle branch block in association with infarction occurred with an unusually high frequency (32%). Ventricular tachycardia similar in configuration to spontaneous arrhythmia was induced with programmed ventricular stimulation in 33 (83%) of the 40 patients. In 15 (45%) of these 33 patients, additional morphologically distinct ventricular tachycardia not seen clinically was initiated. The induction of ventricular tachycardia was not significantly related to the time after myocardial infarction at which spontaneous ventricular tachycardia was initially observed. Only 20 of the 40 patients are alive after a mean follow-up period of 20 +/- 15 months. Twelve of the 20 deaths were sudden cardiac deaths. Sixteen of the 33 patients with inducible ventricular tachycardia died; 8 of the 16 deaths were sudden. By comparison, four of the seven patients with no inducible ventricular tachycardia died (probability [p] = not significant), all suddenly. The mode of therapy did not influence subsequent survival. It appears that in patients with sustained ventricular tachycardia occurring more than 48 hours after a recent myocardial infarction, ventricular tachycardia similar to that clinically observed can usually be induced by programmed stimulation. In addition, multiple morphologically distinct ventricular tachycardias, some of which have not been previously observed, are frequently induced. Finally, the prognosis for survival is poor, regardless of inducibility or mode of therapy, and may in part be related to a changing arrhythmia substrate.

Anatomic-electrophysiologic basis for the surgical treatment of refractory ischemic ventricular tachycardia

Recently developed surgical procedures for the treatment of refractory ischemic ventricular tachycardia have significantly improved the prognosis of patients experiencing these life-threatening arrhythmias. Ventricular tachyarrhythmias associated with ischemic heart disease most commonly originate from the ischemic border zone of myocardial infarctions, where the non-uniformity of tissue injury is most prominent. The inhomogeneity in tissue injury results in desynchronization of electrical wavefront propagation through the ischemic myocardium, thus providing the milieu necessary for the development of micro-reentrant circuits that give rise to the ventricular tachyarrhythmias. Preoperative and intraoperative electrophysiologic mapping techniques are capable of characterizing and localizing such arrhythmogenic myocardium sufficiently to direct the surgeon in his operative approach to the treatment of the arrhythmia. Surgical options include the encircling endocardial ventriculotomy, the endocardial resection procedure, endocardial cryoablation, and combinations or modifications of these three basic procedures. The use of these procedures has made the previously employed indirect surgical procedures obsolete for the treatment of refractory ischemic ventricular tachyarrhythmias.

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.

Extended endocardial resection for the treatment of ventricular tachycardia and ventricular fibrillation

A total of 40 patients with drug-refractory, life-threatening cardiac rhythm disturbances--ventricular tachycardia in 23 patients and ventricular fibrillation in 17 patients--underwent extended endocardial resection (EER) of scar tissue. Scarring was due to myocardial infarction in 38 patients, to previous congenital heart operation in 1 patient, and to sarcoidosis of the heart in 1. The EER procedure was directed by epicardial and endocardial mapping data whenever possible, and was usually combined with revascularization, aneurysmectomy, or, in 5 patients, mitral valve replacement. Operative mortality was 10%, incident to poor preoperative ventricular function and hemorrhage secondary to previous cardiac surgical procedures. Thirty-three of the 36 survivors (92%) are free of arrhythmia at follow-up periods ranging from 3 to 36 months (mean, 12.5 months); the arrhythmia in the remaining 3 patients is now drug controlled. Thirty-three patients had postoperative electrophysiological studies, and in 30 (91%), the arrhythmia was no longer inducible. The results of surgical treatment for ventricular tachycardia and ventricular fibrillation were similar. The results also proved satisfactory whether the EER procedure was directed by visual observation or mapping.

Electrocardiographic changes following endocardial resection for ventricular tachycardia

The ECG changes resulting from endocardial resection, with or without aneurysmectomy and coronary artery bypass grafting (CABG), are reported in 82 patients. Angiographic and surgical features and peak creatine kinase (CK) levels are correlated with ECG findings. Twenty-three of 82 patients (28%) had the following ECG changes postoperatively: decreased ST segment elevation = 3 (4%), loss of R wave amplitude = 4 (5%), increased R wave amplitude = 5 (6%), new Q wave = 4 (4%), axis shift greater than or equal to 45 degrees = 6 (7%), and new bundle branch block = 6 (7%). Five of six new cases of bundle branch block were left bundle type and resulted from resection of the inferoposterobasal and contiguous septal endocardium. ECG anterior infarction, anterior aneurysm, and anteroseptal endocardial resection were associated with a significantly lower incidence of postoperative ECG changes. Aneurysmectomy and the performance of CABG were not significantly associated with postoperative ECG changes, but more bypass grafts per patient grafted appeared in the group with postoperative ECG changes, suggesting that coronary artery disease may be more severe in that group. Peak CK did not correlate with postoperative ECG findings. We conclude that ECG changes occur infrequently after endocardial resection and that the factors responsible are not clear, although severity of coronary artery disease may be contributory. Left bundle branch block is a significant complication of inferoposterobasal resection, but complete heart block appears not to be. The diagnosis of myocardial necrosis is difficult in these patients.

Long-term results of endocardial resection for sustained ventricular tachycardia in coronary disease patients

Sixty patients with recurrent sustained ventricular tachycardia (VT) refractory to medical therapy underwent subendocardial resection. There were 52 men and 8 women, ranging in age from 39 to 74 years, all of whom had coronary disease. Each patient had had a prior infarction 1 week to 11 years prior to surgery and 52 had left ventricular aneurysms. The mean ejection fraction was 27%. All 60 patients underwent endocardial resection with or without aneurysmectomy guided by intraoperative and/or catheter endocardial mapping. Thirty-seven endocardial resections were from the interventricular septum, 14 from the interoposterior free wall, and 16 were from the anteroapical and anterolateral free wall. There were five (8%) surgical deaths. The 55 survivors underwent programmed stimulation in the control state 28 days following the operation. VT was not inducible in 42 patients (group A) and was inducible in 13 patients (group B). The group B patients underwent drug testing and were discharged on the antiarrhythmic agent that made the VT noninducible or more difficult to induce. There have been only four recurrences in sustained VT with a follow-up of 19 +/- 11 months. There have also been nine late nonarrhythmic deaths. The actuarial survival curve predicted 62% survival at 40 months. We conclude that activation guided endocardial resection provides long-term effective therapy for drug-resistant ventricular tachycardia.

Encircling endocardial ventriculotomy for refractory ischemic ventricular tachycardia. III. Effects on regional left ventricular function

In order to assess the effects of the encircling endocardial ventriculotomy (EEV) on regional left ventricular function, we cannulated seven adult mongrel dogs for cardiopulmonary bypass. Two pairs of miniature pulse-transit transducers were placed in mid-myocardium of the left ventricle, one pair in a region that would later be encompassed by an EEV and the other pair in a region of remote normal myocardium. Pressure-dimension data were analyzed during vena caval occlusions (after volume loading) both on and off cardiopulmonary bypass and both before and after performance of an EEV. The EEV results in a significant decrease in diastolic compliance of the encompassed myocardium. No significant compliance changes occurred in the control regions of the same hearts. This change in regional diastolic compliance is partially responsible for a loss of systolic excursion within the EEV-encompassed region and may help to explain the severe left ventricular dysfunction that has been observed in some patients following an EEV.

Encircling endocardial ventriculotomy for refractory ischemic ventricular tachycardia. I. Electrophysiological effects

The direct endocardial surgical techniques introduced for the treatment of refractory ischemic ventricular tachyarrhythmias have resulted in decreased surgical mortality rates and increased success rates in comparison to previous indirect techniques. Since the mechanism of action of one of these new techniques, the encircling endocardial ventriculotomy (EEV), is unknown, the present study was designed to clarify the electrophysiological effects of this procedure. Epicardial and intramural electrophysiology was studied in 18 dogs before and after undergoing an EEV. In the absence of induced myocardial ischemia, the procedure caused an epicardial conduction delay of 23 +/- 3 msec (p less than 0.0001) across the boundaries of the incision. When the EEV enriched acutely ischemic myocardium, it was capable in certain instances of isolating spontaneous ventricular electrical activity to the myocardium encompassed by the incision and thereby protecting the remainder of the heart from the arrhythmia. The EEV resulted in total ablation of all (2 Mv/msec) electrical activity at 20 of 48 (42%) subendocardial electrode sites and at 12 of 44 (27%) subepicardial sites monitored within the encompassed myocardium. These data suggest that although the EEV may be capable of isolating ischemic ventricular tachyarrhythmias to the encompassed myocardium, it most commonly ablates the anatomic-electrophysiological substrate necessary for the genesis and perpetuation of these arrhythmias.

Surgical treatment of constrictive fibrous endocarditis

Between 1971 and 1980, 20 patients with fibrous endocarditis were treated by resection of ventricular endocardium and replacement of the atrioventricular valve. There were 13 male and seven female patients whose ages ranged between 12 and 58 years. Thirteen were white and the remaining seven were black Africans. Nine presented a right-sided form, five a left-sided one, and six presented involvement of both ventricles. The role of hypereosinophilia is discussed in the etiology of the disease. The operation was performed according to the techniques we had developed in our first operative case-excision of the atrioventricular valve. Complete resection of the endocardium, and valvular replacement. There were three operative deaths. Complete atrioventricular dissociation was observed in seven of our patients. particularly in those with right-sided endocarditis. At late follow-up, we have not observed any case of recurrence of the disease. On the basis of our experience and the results previously published in the literature, we believe that endocardiectomy is the best current treatment of this disease.