Operation for recurrent ventricular tachycardia. Predictors of short- and long-term efficacy

The success of ventricular operation in ablating drug-refractory ventricular tachycardia secondary to ischemic heart disease varies with surgical technique, the presence of certain identified risk factors, and patient selection biases. Forty-eight patients with drug-refractory ventricular tachycardia secondary to ischemic heart disease underwent directed ventricular operation. All patients had previous myocardial infarction, and 46 of 48 patients had a left-ventricular aneurysm. Mapping was done in 81% of patients. Patients underwent a combination of subendocardial resection, aneurysmectomy, and cryoablation. The operative mortality rate was 8%. Age greater than 65 years was the only risk factor for operative mortality. Forty-one patients underwent postoperative programmed electrical stimulation. In 26 patients (63%) tachycardia was noninducible, whereas it was inducible in 15 patients (37%). Stepwise logistic regression identified septal and inferior focus location as the most significant predictors of outcome. Septal focus location was a significant (p = 0.008) predictor of surgical success whereas inferior focus location was a significant (p = 0.015) predictor of surgical failure. Other identified independent risk factors for surgical failure were (1) use of cardioplegia, (2) lack of a completed intraoperative endocardial map, and (3) decreased ejection fraction. This generated model to predict success or failure had a sensitivity of 93.3% and a specificity of 92.4%. The success of ventricular operation is affected by the presence of certain risk factors. In the management of those patients at high risk for failure, other surgical options such as the placement of implantable cardioverter-defibrillator electrode patches at the time of ventricular operation or the alternative placement of a palliative implantable cardioverter-defibrillator should be considered.

Numerical model for radio-frequency ablation of the endocardium and its experimental validation

A theoretical model for the study of the radio-frequency (RF) ablation technique is presented. The model relies on a finite-element time-domain calculation of the temperature distribution in a block of tissue, resulting from the flow of RF (< 1MHz) electrical current. A thermal damage function is used to calculate the extent of the lesion on the basis of the temperature elevation and the duration of exposure. This work extends the model proposed by Haines [1] by including a more realistic and variable geometry, the cooling effect of the blook flow and a transient analysis. Furthermore, the nonlinearity caused by the temperature dependence of the tissue properties is also considered. The complexity of the model being appreciable, an experiment demonstrating its validity is also described. While remaining workable, the experiment is sophisticated enough to lead to convincing conclusions. It consists in measuring the temperature distribution and the time-dependent electrode resistance during "ablation" of a tissue-equivalent material. Various electrode configurations and electrical excitations are investigated. In all cases, the experimental results agree reasonably well with the numerical calculations. This confirms that the model is accurate for the investigation of RF ablation.

Surgical interventions in ischemic ventricular tachyarrhythmias--endocardial resection or implanted cardioverter/defibrillator

The surgical therapy of ventricular tachyarrhythmias (VTA) in ischemic heart disease is attracting attention, since current medical therapies are showing limited long-term efficacy. The curative concept of electrophysiologically guided endocardial resection (ER) and palliation with the implantable cardioverter/defibrillator (ICD) are compared retrospectively. From 1980-1992, 121 patients (55 +/- 9 years, 108 males, 13 females) underwent ER and 203 patients (59 +/- 9 years, 195 males, 8 females) received an ICD for ischemic VTA. Concomitant coronary revascularization was performed in 38/121 patients with ER (31%) and in 62/203 patients (31%) with ICD. Perioperative mortality was 8% (10/121 patients) for ER and 5% (10/203 patients) for ICD (P = n.s.). Hundred eleven patients with ER (mean follow-up 41 +/- 37 months) and 193 with ICD (mean follow-up 22 +/- 20 months) were available for survival analysis: freedom from sudden death was comparable for the two groups at 1 year (99% for ICD, and 94% for ER) and at 5 years (90% for ICD and 90% for ER) (P = n.s.). Freedom from cardiac death also showed no differences between the groups at 1 year (94% for ICD, and 84% for ER) and at 5 years (74% for ICD and 74% for ER) (P = n.s.). Left ventricular function, indicated by left ventricular ejection fraction, was comparable (34 +/- 9% in ER, 30 +/- 11% with ICD) (P = n.s.) in the two groups. The linearized incidence of DC-shocks was 10.3/year in ICD patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Recognition and catheter ablation of subepicardial accessory pathways

OBJECTIVES

The purpose of this study was to characterize left-sided accessory pathways that traverse the atrioventricular (AV) groove subepicardially and to describe results of radiofrequency catheter ablation within the coronary sinus in the patients studied.

BACKGROUND

Radiofrequency catheter ablation has proved to be a safe and effective method for treatment of accessory pathways; however, subepicardial accessory pathways may account for some of the failures encountered during endocardial ablation.

METHODS

The study group comprised 51 consecutive patients with a left-sided accessory pathway who were undergoing radio-frequency catheter ablation. Initially, the ablation catheter was introduced into a femoral artery and positioned on the ventricular aspect of the mitral annulus. If this endocardial approach was unsuccessful, the ablation catheter was introduced into the coronary sinus and energy applied at sites with shorter activation times than those recorded from the endocardium.

RESULTS

Five (10%) of 51 patients with a left-sided accessory pathway could not have accessory pathway conduction interrupted with a median of 18 endocardial radiofrequency energy applications. Accessory pathway potentials were less frequent during endocardial mapping in these 5 patients than in the 46 patients whose accessory pathway was successfully ablated from the endocardial surface. All five of these patients later had successful ablation using one or two applications of radiofrequency energy from within the coronary sinus. Effective target site electrograms in the coronary sinus were characterized by an accessory pathway potential that was larger than the corresponding atrial or ventricular electrogram. There were no complications or recurrences after ablation within the coronary sinus.

CONCLUSIONS

Some left-sided accessory pathways may be difficult to ablate from the endocardial surface because they traverse the AV groove subepicardially. The absence of an accessory pathway potential during endocardial mapping in combination with a relatively large accessory pathway potential within the coronary sinus may be a useful marker of a subepicardial pathway. In this select group of patients, radiofrequency catheter ablation from within the coronary sinus appears to enhance efficacy.

[An experimental study of catheter ablation using microwave energy via coaxial electrode catheter]

The purpose of this study was to examine the efficacy, arrhythmogenicity, and the size of ablated lesions of catheter ablation with microwave energy. Microwave energy generated by a device with a frequency of 2450 MHz, was delivered via a bipolar electrode coaxial catheter with an electrode ball tip. Microwave ablation was applied (50 watts for 15-150 sec.) on the left ventricular endocardium in 6 dogs. No ventricular arrhythmia occurred during ablation in any of the dogs when microwave catheter ablation was applied for less than 45 sec. However, when the duration of microwave catheter ablation was longer than 45-60 sec, ventricular premature contractions were observed in all 6 dogs. When ablation time was set for a longer time, the dogs developed nonsustained ventricular tachycardias. Nevertheless, ventricular arrhythmias after ablation did not occur in all dogs. Ventricular programmed stimulation after ablation did not induce ventricular tachycardia in any of the dogs. When ablation time lasted more than 120 sec, the coagulation layer was extended to the epicardium in all 6 dogs. The results of this study suggest that microwave ablation is feasible for the treatment of tachyarrhythmias from a deep focus of the ventricular myocardium.

Comparison of the usefulness of the implantable cardioverter-defibrillator and subendocardial resection in patients with sustained ventricular arrhythmias and poor regional wall motion associated with coronary artery disease

The implantable cardioverter-defibrillator (ICD) and subendocardial resection are effective forms of therapy for sustained ventricular arrhythmias associated with coronary artery disease in selected patients. The relative efficacy of these 2 treatments in equivalently matched patients is not known. A regional wall motion score has been shown to be a powerful predictor of long-term outcome after both ICD implantation and subendocardial resection. This study retrospectively analyzed the long-term outcome of patients with coronary artery disease and ventricular arrhythmias treated during the same period with an ICD (n = 53) or by subendocardial resection (n = 65). Treatment outcomes were compared in subgroups determined by preoperative regional wall motion scores of either < or = 16 or > 16%. The 3-year cardiac mortality of the 2 therapies was not significantly different among patients with a wall motion score of > 16% (0% ICD vs 11% endocardial resection) or of < or = 16% (41% ICD vs 35% endocardial resection). Similarly, the 3-year sudden cardiac death mortality was similar among patients with a score of > 16% (0% for both ICD and endocardial resection) or of < or = 16% (9% ICD vs 14% endocardial resection, p = NS). At 24 months after hospital discharge, the percentage of patients who were in New York Heart Association functional class I or II was similar among patients with a wall motion score of > 16% (75% ICD vs 86% endocardial resection, p = NS) or with a wall motion score of < or = 16% (26% ICD vs 45% endocardial resection, p = NS).(ABSTRACT TRUNCATED AT 250 WORDS)

Prevention of acute regional ischemia with endocardial laser channels

Laser myocardial revascularization has been shown to reduce mortality and infarct size after left anterior descending coronary artery (LAD) ligation in dogs. It has not been shown to improve myocardial contractility in acute ischemia. In this study a holmium-yttrium-aluminum garnet laser (wavelength, 2.14 microns) was used to create nontransmural myocardial channels from the endocardial surface in the ischemic regions of the canine left ventricle. Twelve mongrel dogs (6 controls, 6 laser myocardial revascularizations) underwent 90 minutes of LAD ligation followed by 6 hours of reperfusion. The ischemic region was determined by methylene blue injection during brief LAD occlusion. Laser myocardial revascularization averaged three channels per square centimeter in the ischemic region created using 12 J/channel (600 mJ/pulse, 10 Hz) before LAD ligation. Contractility was assessed from regional preload recruitable stroke work (RPRSW), using pairs of segment length ultrasonic transducers in the ischemic and the nonischemic regions. Two-dimensional echocardiography corroborated with segmental length findings. In control dogs, the ischemic region was dyskinetic during LAD ligation and reperfusion. Dyskinesis of the ischemic region during systole produced negative values for regional stroke work, and RPRSW was considered zero. In 4 of 6 laser-revascularized dogs, RPRSW remained positive in the ischemic region. Two dogs had intermittent dyskinesis. The difference between laser-revascularized and control dogs in ischemic region RPRSW was significant (p < 0.01 by Fischer's exact test).(ABSTRACT TRUNCATED AT 250 WORDS)

Temperature-guided radiofrequency catheter ablation with very large distal electrodes

BACKGROUND

Previous studies have shown that the size of lesions produced by radiofrequency catheter ablation correlates with the temperature and surface area of the electrode-tissue interface. The purpose of the present study was to compare the effects of ablation using very large distal electrodes (8F, 8 and 12 mm long) with those made by a conventional radiofrequency ablation catheter (distal electrode 8F, 4 mm long).

METHODS AND RESULTS

Each catheter had a thermistor in the tip of the distal electrode. Radiofrequency energy (500 kHz) was supplied by a generator that continuously monitored temperature and produced up to 100 W. In 10 dogs, each of the three ablation catheters were introduced percutaneously and positioned under fluoroscopic guidance at disparate left ventricular endocardial sites. Radiofrequency power output was titrated to achieve a temperature of 80 degrees C for 60 seconds at each ablation site. The power required to produce a steady-state temperature of 80 degrees C was directly proportional to electrode size (15 +/- 7, 46 +/- 15, and 62 +/- 32 W using the 4-mm-, 8-mm-, and 12-mm-long electrodes, respectively). Lesions produced by the 8-mm electrode were nearly twice as deep (11 +/- 2.4 versus 6 +/- 1.2 mm, P < .001) and four times as large (905 +/- 410 versus 210 +/- 100 mm3, P < .001) as those made with a conventional 4-mm electrode. Lesions produced by the 12-mm electrode were intermediate in size (depth, 8 +/- 1.2 mm; volume, 465 +/- 225 mm3) and sometimes were associated with charring and crater formation. Ablation with the larger electrodes caused a drop in arterial pressure and more ventricular ectopy than ablation using a 4-mm distal electrode.

CONCLUSIONS

Thermistor-equipped elongated ablation electrodes coupled to high-power outputs can reproducibly produce lesions approximately 1 cm in diameter. This system may prove useful for ablation of ventricular tachycardias in patients with coronary artery disease.

[Long-term follow-up of anti-tachycardia surgery in patients with ventricular tachycardia]

From March 1980 to May 1992 mapping guided surgery was performed in 132 patients with drug-refractory recurrent ventricular tachycardia. There were 121 patients (group I) with coronary disease and 11 patients (group II) had noncoronary ventricular tachycardia. Patients in group I underwent subendocardial resection and cryoablation was performed in group II patients. Perioperative mortality (< 30 days after surgery) was 8% (10/132 patients). During the mean follow-up of 41 +/- 24 months, 37/122 patients (30%) died, 35/111 patients in group I (32%) and 2/11 patients in group II (18%) (p = 0.29). In group I, sudden death occurred in 8/111 patients (7%) and cardiac death in 23/111 patients (21%); in group II, 1/11 patients (9%) died from sudden and 1/11 patients (9%) from cardiac death. Nonfatal recurrences occurred significantly more frequently in group II (6/11 patients, 55%) than in group I (16/111 patients, 14%) (p < 0.01). During the follow-up functional class of heart failure improved in 69 patients (57%), remained constant in 27 patients (22%) and decreased in the remaining 26 patients (21%). The surgical approach to control ventricular tachycardia has low rates of sudden death and nonfatal recurrences in patients with drug-refractory ischemic ventricular tachycardia. Patients with noncoronary disease had a high incidence of nonfatal ventricular tachycardia after surgery and should be considered for other therapeutic approaches in the future.

Interstitial cells from the atrial and ventricular sides of the bovine mitral valve respond differently to denuding endocardial injury

The mitral valve has atrial and ventricular sides, each lined by endocardial cells. The valve stroma contains alpha smooth muscle actin positive interstitial cells, collagen, glycosaminoglycans, and elastic tissue. To eliminate the effect of endocardium on wound repair in bovine mitral valve organ culture, the endocardium was removed from both sides of the valve. At 6 days, organ cultures of these preparations revealed surface cells on the ventricular side but not in the atrial side. Ventricular surface cells were negative for Factor VIII-related antigen, and positive for alpha smooth muscle actin. Immunoperoxidase staining for proliferating cell nuclear antigen/cyclin, a marker for cell proliferation, revealed a positive labeling index of (mean +/- standard deviation) 0.08 +/- 0.16% for interstitial cells from the atrial side and 0.14 +/- 0.19% for ventricular side interstitial cells in uncultured preparations (not significant), and 0.44 +/- 0.69% for atrial side interstitial cells and 2.25 +/- 1.64% for ventricular side interstitial cells in the cultured preparations (significant, P < 0.0006). The results suggest that in organ culture, interstitial cells from the ventricular side of the mitral valve respond to a denuding endocardial injury by proliferating and migrating onto the adjacent surface whereas interstitial cells from the atrial side do not. This difference in the response to injury of interstitial cells from the atrial and ventricular sides of the valve may reflect differences in phenotype or may be due to effects of extracellular matrix on interstitial cell behavior. The latter is possible because of differences in the extracellular matrix of the atrial and ventricular sides of the valve.

Argon beam coagulation compared with cryoablation of ventricular subendocardium

The Argon Beam Coagulator uses radiofrequency energy to excite argon gas that may be used for ventricular ablation. The effects of power level and number of applications of the Argon Beam Coagulator were compared wtih cryothermia. Ten mongrel dogs underwent cardiac extirpation. The endocardial surfaces of 5 hearts were used for the creation of lesions using the Argon Beam Coagulator at five power levels with either one or two applications. Five hearts were used for endocardial and epicardial lesions using cryothermia (15-mm-diameter probe at -70 degrees C) for 1, 2, 3, or 4 minutes. The Argon Beam Coagulator lesions showed an increase in depth with increasing power levels (2.25 +/- 1.05 mm at 50 W to 6.64 +/- 0.75 mm at 150 W) and number of applications (maximum depth of 6.64 +/- 0.75 mm with one application, 11.2 +/- 1.1 mm with two applications). Cryothermia lesions were similar in depth regardless of duration or site of application (range, 6.1 to 10.2 mm). Both techniques resulted in homogeneous and well-demarcated lesions. These data show that the Argon Beam Coagulator results in discrete endocardial lesions, which may be created quickly and reproducibly. This may be a useful alternative for the operative ablation of endocardial scar in the treatment of ventricular tachycardia.

Outcome of endocardial resection in 33 patients with coronary artery disease: correlation with ventricular tachycardia morphology

The results in 33 patients with ventricular tachycardia (VT) treated by endocardial resection were reviewed, with special emphasis on the presence of single or multiple morphologies preoperatively and intraoperatively. Multiple VT morphologies were induced in 16 patients and a single VT morphology was induced in the remaining 17. Intraoperative programmed stimulation failed to induce VT in eight patients and visually-directed endocardial resection was performed. The remaining patients underwent map-guided resection. The surgical success rate did not correlate with any morphologic characteristics of the VT, such as bundle branch block pattern or axis. In addition, concordance of VT morphologies preoperatively and intraoperatively before resection did not correlate with the surgical success rate. However, patients in whom multiple morphologies of VT were induced intraoperatively had a significantly higher success rate (100%) compared with those patients in whom only a single morphology was induced intraoperatively (50%, p < 0.05). Long-term follow-up was maintained in 26 patients. Ventricular tachycardia recurred in two patients and VF recurred in two others who did not have inducible VT 1 week after endocardial resection. In conclusion, neither the preoperative morphologic characteristics of VT nor discordance between the morphologies of VT induced preoperatively and in the operating room influenced the outcome of endocardial resection. However, the surgical success rate is higher when multiple morphologies of VT are inducible in the operating room than when only one VT morphology is inducible.

Comparison between laser and electrical ablation of ventricle in dogs: hemodynamic, pathologic and electrocardiographic observations

To characterize and compare the pathologic, hemodynamic and electrocardiographic changes of both transcatheter laser and electrical energy on ventricle, 36 subendocardial myocardium lesions were induced at energy 60, 120 and 240 Joules by either transcatheter laser irradiation or electrical shock in 7 anesthetized dogs. The following results were observed: 1) Both laser and electrical ablation on myocardium created nonhomogeneous myocardium injury, but laser ablation caused mainly focal tissue vaporization and necrosis, while electrical shock induced widespread tissue degenerations; 2) Both laser and electrical induced-lesion dimensions increased parallel to the total dosage of energy; 3) Laser ablation caused mainly (90%) single ventricular premature beats and 86% of them occurred within the first minute after energy discharged, while ventricular tachycardias were found in any electrical energy groups; ventricular fibrillations occurring during laser and electrical ablation were 5% and 13% respectively (P < 0.01); 4) A decrease in aortic blood pressure and an increase in central venous pressure induced by laser ablation were significantly less than that produced by the same amount of electrical energy (P < 0.01). Our preliminary results have shown that transcatheter laser ablation has great potential for becoming a practical method in the management of refractory tachycardias.

Predictors of surgical mortality and long-term results of endocardial resection for drug-refractory ventricular tachycardia

The results of surgical therapy performed in 51 consecutive patients with ventricular tachycardia were reviewed to determine short- and long-term predictors of success of such therapy in preventing recurrences of life-threatening ventricular arrhythmias. Of 41 patients (80%) who survived surgery, 40 had postoperative programmed stimulation and, of these patients, 78% (n = 31) had no inducible ventricular tachycardia on no antiarrhythmic therapy. This group had a very low incidence of arrhythmia recurrence, with only one nonfatal episode of ventricular tachycardia after a mean follow-up of 41 +/- 30 months. In contrast, two of the nine patients (22%) who had inducible arrhythmias postoperatively had cardiac arrest (p = 0.12). Multivariate analysis identified two significant predictors of perioperative mortality in our patients: increased duration of cardiopulmonary bypass time and increased baseline pulmonary capillary wedge pressure. It is concluded that (1) patients who do not have inducible ventricular tachycardia after arrhythmia surgery have a very low incidence of recurrent arrhythmia and (2) prolonged time of cardiopulmonary bypass and increased pulmonary capillary wedge pressure are predictive of perioperative mortality.

[Ischemic cardiomyopathy: remodeling, hypertrophy, subendocardial risk. Can processes be controlled?]

Ischaemic cardiomyopathy reflects the myocardial dysfunction caused by coronary disease. It results from the association of 1. segmental infarction(s) responsible for ventricular "remodelling", i.e. expansion of the necrotic area(s) and hypertrophy-dilatation of the rest of the ventricle, eventually concurring to heart failure; 2. areas which are viable but with a function that is reversibly compromised by severe acute or chronic ischaemia (myocardial sideration or hibernation) affecting mainly the subendocardium. The spontaneous course of cardiomyopathy towards the worst can be arrested by 1. revascularisation of the myocardium at risk by coronary reperfusion performed either as an emergency in case of infarct in the process of formation, or after detection of the viable myocardial areas by isotopic methods; 2. prevention or limitation of ventricular remodelling by coronary reperfusion and improvement of the ventricular load by administration of angiotensin-converting enzyme inhibitors and nitroglycerin. The Survival and Ventricular Enlargement study (SAVE) has been the first to demonstrate the relationship between limitation of ventricular remodelling and improvement of the secondary prognosis of infarction obtained by angiotensin-converting enzyme inhibitors.

Does a posterior aneurysm increase the risk of endocardial resection?

The bias has been that the ideal anatomic circumstance for endocardial resection is the anterior left ventricular location. Posterior left ventricular aneurysms have been thought to be problematic to map and more difficult to close, and possibly to have a different substrate for ventricular tachycardia. To address this problem, we retrospectively reviewed the cases of 110 consecutive patients who underwent sequential endocardial resection for ventricular tachycardia between 1983 and 1991. Ninety-six patients had an anterior aneurysm, and 14 patients had a posterior aneurysm or infarct. Operative survival and 5-year survival were very similar between the two groups (p = not significant). A positive postoperative electrophysiological study was present in 11% of the anterior group versus 14% of the posterior group (p = not significant). There was a significantly greater incidence of mitral valve replacement in the posterior group, and we believe this was most likely due to frequent localization of the arrhythmia to the papillary muscle. Otherwise, patients with a posterior aneurysm or infarct had surgical results equivalent to those in patients with an anterior location. As long as there is a discrete aneurysm or infarct, endocardial resection is a safe and effective therapeutic procedure for ventricular tachycardia.

[Surgical treatment of ventricular tachycardia in patients with post-infarction aneurysms]

4 patients (P) with recurrent, sustained ventricular tachycardia (VT) resistant to medical treatment, underwent surgery for cure of this arrhythmia. Each P had episodes of VT lasting 30 or more seconds, 3 of them had episodes of ventricular fibrillation. In all cases rhythm disturbances were secondary to post myocardial infarction aneurysm. Coronary angiography showed in all P total occlusion of LAD, in 2 cases significant lesion in RCA were found. 1 P had lung cancer. All P underwent aneurysmectomy and an excision of the altered endocardium by Harken's method. The endocardial excision was performed without endocardial mapping. 2 P had concomitant CABG to RCA. In the P with lung cancer lobectomy was performed. There were 2 ++non-arrhythmic death. The P with lung cancer died because of sepsis due to lung abscess. One P died because of heart failure (preoperative EF 10%), 6 months after the surgery. The 2 survivors remained free of VT during a follow-up period 8 months. In conclusion, endocardial excision by Harken's method is efficient in treating recurrent sustained VT, resistant to medical treatment, in patients with post myocardial infarction aneurysm. The surgical procedure can be performed without intraoperative endocardial mapping.

[A useful method for the surgical treatment of active infective endocarditis--a case report using the Teflon felt reinforcing method]

In the surgical treatment for active infective endocarditis (IE), perivalvular leakage is the most severe complication. We had a 42-year-old man who had active IE and a giant vegetation in the aortic valve, and a small mycotic aneurysm in the left ventricular outflow tract. Other operative observations included slight redness and a decrease in the reflex of the annular endocardium. We made a patch closure of the mycotic aneurysm, and aortic valve replacement using the Teflon felt reinforcing method. In the postoperative course, he had a pacemaker implantation with complete AV block. Postoperative pathological examination revealed inflammatory cells and plasma infiltration, and edematous change of the interstitial tissue around the cusp surface and annular side of the resected valve. These pathological changes could explain the redness and the decrease in the reflex of the annular endocardium. The edematous changes of the annular tissue might be the cause of postoperative perivalvular leakage. Reinforcement of the prosthetic valve with Teflon felt might be a useful method to prevent perivalvular leakage. There is, however, the possibility of acceleration or elongation of infective endocarditis. In our experiences of the surgical treatment for active IE, we performed valve replacement using Teflon felt in 6 patients, and not using in 27 patients. The mean period until CRP had been normalized was no significant difference between both groups (mean days using Teflon felt were 63.5 days, and not using were 75 days).(ABSTRACT TRUNCATED AT 250 WORDS)

Surgical therapy for drug-refractory ventricular tachycardia: role of additional aneurysmectomy or bypass grafting

To assess whether additional aneurysmectomy and/or bypass grafting influence prognosis we studied 97 patients with recurrent sustained monomorphic ventricular tachycardia after an old myocardial infarction. All patients underwent subendocardial resection due to drug-refractory ventricular tachycardia. There were 41 patients who had resection alone, 27 patients had resection and aneurysmectomy, 13 patients had resection and bypass grafting and the remaining 16 patients had resection with both, aneurysmectomy and bypass grafting. During the mean follow-up of 40 +/- 27 months 29 patients died (30%) (total mortality), 7 patients suddenly (7%) and 20 patients from cardiac causes (20%). There were no significant differences in total mortality between patients with resection alone (32%), patients with resection and aneurysmectomy (22%), patients with resection and bypass grafting (31%) and patients who had resection, aneurysmectomy and bypass grafting (38%). In addition, no significant differences were observed in the incidence of sudden death and nonfatal recurrences between patients with resection alone: sudden death 12%, recurrences 7%; patients with resection and aneurysmectomy: sudden death 0%, recurrences 19%; patients with resection and bypass grafting: sudden death 0%, recurrences 8%; and patients with resection, aneurysmectomy and bypass grafting: sudden death 13%, recurrences 0%. Postoperatively, left ventricular function improved in 56% of patients who had resection and aneurysmectomy compared to 17% of patients with resection alone, 31% of patients with resection and bypass grafting and 19% of patients who had resection, aneurysmectomy and bypass grafting. There is a low risk of sudden death and nonfatal recurrences after subendocardial resection. An influence of additional surgical approaches (aneurysmectomy or bypass grafting) on prognosis is not visible.

Superiority of endocardial versus epicardial implantation of the implantable cardioverter defibrillator (ICD)

The implantable cardioverter-defibrillator (ICD) has proved to be an efficient device for the treatment of severe ventricular tachyarrhythmias (VT). From May 1985 to August 1991, the ICD was implanted in 107 patients of whom 72% suffered from coronary artery disease, 17% from cardiomyopathy, 5% from long QT-syndrome and 6% from other heart disease. All patients had a life threatening episode of VT or at least one episode of ventricular fibrillation. Of 107 implants, 12% were combined with other heart surgery, 55% were isolated epicardial implantations (epi I) and in 33%, the novel endocardial (endo I) approach was chosen. Between epi I and endo I we found no difference in operation time, but time for ICU and in-hospital stay was significantly shorter using the transvenous approach. In addition, sensing and pacing capability of the endocardial screw-in electrode was superior and the need for thoracotomy was avoided, a particular advantage in patients with previous heart surgery. Complications after epi I were: temporary low cardiac output, 1; perioperative death, 2; infection, 3, and after endo I: electrode dislocation, 2. Hence, endo I may become the method of choice for patients without concomitant surgery.

[Percutaneous endocardial Nd-YAG laser energy: experimental studies of ablation of the ventricular myocardium]

The in vitro and in vivo effects of endocardial laser ablation were assessed. Energy was supplied by a Nd-YAG laser (wavelength approximately 1064 nm) and transmitted via a quartz core fiber (phi: 0.4 mm) housed within a specially designed 7 F catheter. In vitro, the effects of increasing output power (5, 10, 20, 40 watt) and impulse duration (1, 2, 4, 8 s) on lesion size were assessed in myocardial preparations of canine hearts. Preparations were superfused with saline or blood, respectively; the distance of the optical fiber to the endocardium was 5 mm. Lesion size increased in diameter (range: 0-4.0 mm) and depth (range: 0-5.2 mm) in a power- and time-dependent manner. Superfusion with blood significantly enhanced the diameter of the lesions, whereas depth of the lesions significantly decreased. In 16 anesthetized mongrel dogs, a total of 52 laser impulses (output power: 10, 20, 40 w; impulse duration: 1, 2, 4 s; energy: 10-160 J) were delivered to apical and apico-inferior sites of the left ventricle. Postmortem, 40 lesions with a diameter of 2.6-19.4 mm and a depth of 3.7-16.2 mm were found. 19 lesions revealed central vaporized craters with a depth up to 11.2 mm. Perforation of the left ventricle occurred in two cases following 80 and 160 J, respectively. In vitro and in the intact animal (in apical and apico-inferior sites of the left ventricle) endocardial laser ablation is feasible to induce distinct myocardial lesions in a power- and time-dependent manner.(ABSTRACT TRUNCATED AT 250 WORDS)

Amiodarone-related postoperative adult respiratory distress syndrome

Directed surgical intervention in patients with ventricular tachyarrhythmias who have experienced failure of amiodarone therapy is a common clinical scenario. Sixty-seven patients with malignant ventricular tachyarrhythmias received either an automatic implantable cardioverter-defibrillator (n = 43) or subendocardial resection (n = 24). Nineteen cardiothoracic procedures (automatic implantable cardioverter-defibrillator in six, endocardial resection in 13) were performed in 17 patients who received amiodarone before surgery. Eight received the drug acutely as a loading dose of 1,200 mg/day for 7-14 days; 11 patients were on chronic oral amiodarone at a mean dose of 362 +/- 74 mg/day. Eight patients were removed from amiodarone therapy a mean of 6.6 days before surgery. Adult respiratory distress syndrome (ARDS) developed after surgery in nine (50%) of 18 surgical survivors. ARDS was manifested by hypoxemia, pulmonary infiltrates, and prolonged intubation. Pulmonary capillary wedge pressure and cardiac output were measured before and after surgery and during ARDS. Pulmonary capillary wedge pressure and cardiac output remained constant after surgery at a time that the PaO2/FIO2 ratio fell significantly. By contrast, none of the remaining 44 patients who did not receive amiodarone developed ARDS despite similar preoperative and intraoperative clinical parameters. Patients with ventricular tachyarrhythmias who receive even a short course of amiodarone are at risk for postoperative ARDS.

Surgical treatment of cardiac arrhythmias

This report describes 20 consecutive patients who underwent surgical procedures for treatment of cardiac arrhythmias. 16 patients have been operated for WPW syndrome, always using the epicardial approach, without extracorporeal circulation. Three patients underwent surgery for atrio-ventricular nodal reentrant tachycardia, using a discrete perinodal cryotreatment, during normothermic extracorporeal circulation. In one case we used cryoablation of the atrial myocardium below the coronary sinus to treat atrial flutter. This operation was performed under normothermic extracorporeal circulation. In our observations, there was no early or late death; postoperative complications developed in 1 patient (5%) due to pericarditis. Ablation of the AP was completely successful in all the cases (100%) operated for WPW as well as for AVNRT syndromes and atrial flutter.

The influence of preoperative shock on outcome in sequential endocardial resection for ventricular tachycardia

Sequential endocardial resection was used in 92 consecutive patients to treat ventricular tachycardia. All patients had coronary artery disease with previous myocardial infarction. All patients had repeated cycles of mapping and resection of arrhythmogenic foci in the normothermic beating heart until ventricular tachycardia was no longer inducible. Eighty-six patients (93%) survived to hospital discharge. The survival rate in patients normotensive at the time of operation was 98% and in patients in shock at the time of operation, 43%. By Cox regression analysis, preoperative shock was the significant predictor (p less than 0.001) of operative mortality. Seventy-four of the 86 operative survivors (86%) had no sustained ventricular tachycardia at initial postoperative electrophysiologic study when receiving no antiarrhythmic drugs. Eighty-three of the 86 operative survivors (97%) had no sustained ventricular tachycardia at final postoperative electrophysiologic study when using antiarrhythmic drugs as needed. After a median follow-up of 21 months (range 1 to 79 months) there were 4 sudden cardiac deaths, 12 other cardiac deaths, and 3 noncardiac deaths. There were no documented nonfatal episodes of sustained monomorphic ventricular tachycardia after hospital discharge. Use of the sequential endocardial resection technique is effective in curing ventricular tachycardia with low operative morbidity and mortality.

Non-pharmacological therapy of atrial fibrillation and flutter

Atrial fibrillation and atrial flutter are the most frequent arrhythmias encountered by the cardiologists in an everyday practice. External cardioversion, atrial temporary pacing and/or drugs are commonly and often successfully used in their treatment. The failures of these methods are rare, and for the patients who remain prone to arrhythmias or a recurrence with serious hemodynamic consequences, new therapies are presently under assessment. Electrical internal cardioversion can be performed when a permanent and bad tolerated atrial fibrillation is not managed by an external cardioversion. Elective ablation of a reentrant area will be probably the best solution to treat a recurrent atrial flutter or a junctional tachycardia by intranodal reentry. Finally, a radical solution consists to separate electrically the atria from the ventricles by interrupting totally or partially the A-V conduction. This can be performed by an endocavitary fulguration or an ablation by radiofrequency currents. To avoid recurrences, we usually use a pharmacological therapy. Permanent pacing is an exceptional solution.

Endocardial resection in the treatment of ventricular tachycardia secondary to cardiac trauma

Sustained ventricular tachycardia with left ventricular aneurysm formation is a rare complication following penetrating cardiac trauma. We present an unusual case of serious ventricular tachycardia which developed 35 years after a World War II injury and was successfully treated with aneurysmectomy, map-guided subendocardial resection, and cryoablation.

[Intracardiac repair in left ventricular rupture following mitral valve replacement]

Rupture of the left ventricle is one of the major lethal complications of mitral valve replacement. We have encountered 11 cases of this complication over a period of 19 years (1971, Apr.-1990, Mar.). Five of 8 cases of intraoperative rupture survived but no patient survived a delayed rupture. In the patients with intraoperative rupture external repair was performed in 6 cases, resulting in 3 survivors, two in type II and one in type I with formation of left ventricular false aneurysm. For selection of surgical treatment accurate recognition of types of rupture is important but the location and size of the endocardial and epicardial defects do not always correspond. Attempts to suture a ventricular rupture on the pressure-loaded beating heart were always unsuccessful and frequently extended the tear. Repair should be accomplished with aid of cardiopulmonary bypass on the decompressed and arrested heart. Recently, we chose internal repair with arrested heart in 2 cases of type I rupture, that is, reopening of the left atrial closure and repair from within the cardiac chamber with removal of the prosthetic valve. Both cases survived. In conclusion, we emphasized importance of intracardiac repair with removal of the replaced prosthetic valve in left ventricular rupture of type I and III following mitral valve replacement for better exposure, more secure repair, and prevention of injury to the circumflex artery.

Repetitive intraoperative mapping and cryotherapy improve the results of endocardial resection for ventricular tachycardia

Patients with recurrent ventricular tachycardia or a history of a sudden cardiac death episode and ventricular tachycardia inducible in the electrophysiology laboratory have a high incidence of recurrence and a high mortality despite medical therapy. Map-guided endocardial resection has improved treatment results, but is associated with a 10-30% failure rate. In our initial experience with endocardial resection (Group I) we incurred a 30% treatment failure rate. In the present study we have found the addition of sequential intraoperative mapping and routine use of cryotherapy (Group II) improved our results of ventricular tachycardia control without significant additional morbidity or mortality.

[Surgical treatment of non-ischemic ventricular tachycardia]

The authors reviewed the results of 42 operations for non-ischemic ventricular tachycardias, tachycardia being arrested by laser ablation in 2 cases. Right and left ventricular tachycardias were seen in 26 and 14 patients, respectively. For diagnosis, preoperative electrophysiologic study, intraoperative epicardial mapping, and "delayed" potentials were used. In 38 of 40 patients who had undergone a direct operation, a positive result was obtained; in 31 patients, a complete disappearance without applying antiarrhythmics was observed. Four patients received drug therapy which proved to be ineffective before surgery. Two patients died after surgery due to recurrent tachycardia. Out of 38 survivals, 3 died of heart failure that was not caused by recurrent tachycardia.

[Surgical treatment of cardiac arrhythmia]

The data available in the literature show that application of indirect tools (sympathectomy, aortocoronary bypass, aneurysmectomy) provide good results in abolishing ventricular tachycardias approximately in 57% of cases. In this connection, quite a number of new so-called direct operations on arrhythmia substrates have been developed. These include circular endocardial ventricular resection, extensive fibrous endocardial resection, fibrous endocardial resection under the monitoring of beating heart mapping, cryo-, and laser exposures. The author has his own good results: the operative mortality is 12% in patients with coronary heart disease and ventricular tachycardias. Thus, the author's findings indicate that 5 years later 75% of the patients who had undergone a direct operation for ventricular tachycardia were alive.

[Variants of surgical treatment of ventricular tachycardia]

The paper presents the practice of the Hannover++ Surgery Center (FRG) in managing ventricular tachycardias: 122 patients underwent a radical operation by using electrophysiological studies, 92 patients were implanted an automatic cardioverter/defibrillator, 12 had homotopic cardiac transplantation. Coronary heart disease was present in 82%, non-ischemic heart disease was seen in 18%. The outcomes of operations with electrophysiological studies were as follows: deaths were 9% in early periods, relapses occurred in 5% of patients with coronary heart disease and in 46% of non-coronarogenic diseases. The cardioverter/defibrillator was implanted in 71 patients with coronary heart disease and 21 patients with non-coronarogenic diseases. The mean ejection fraction was 32%. The early and late mortality rates were 5 and 19%%, respectively. Out of 19 patients who had undergone transplantation, 17 were alive in follow-ups of 3 to 36 months. The ejection fraction before transplantation averaged 17%. The surgery for ventricular tachycardias with electrophysiological support is a highly effective method of therapy. The implantation of a cardioverter/defibrillator is regarded as a palliative intervention in patients with ventricular malfunction in the absence of an electrophysiological tachycardia substrate or in the presence of polymorphic tachycardia. Cardiac transplantation should be performed chiefly in young patients with evolving major disease. The transplantation may be replaced by implantation of a cardioverter if the former is impracticable or will be performed in future.

[Surgical treatment of Wolff-Parkinson-White syndrome]

The paper presents the data on 365 operations to arrest the Wolff-Parkinson-White syndrome, which were performed in the period of 1973 to July 1989 in the Clinical Hospital, University of Kanazawa. The authors were the first to apply an endocardial access to remove Kent's bundle. They obtained the following results: later on 344 of 365 patients undergone surgery had no recurrent tachycardias. Incomplete abolition was observed in 21 patients, but relapses of tachycardias were absent. A total of 11 patients died within 1 to 32 days of postsurgery. The authors have noted that they achieved 100% positive results in the last series of 101 operations: there was no relapse of tachycardias, repeated operations, atrioventricular block and deaths. At present, the surgical technique for arresting the WPW syndrome has some advantage over drug therapy. The operation fully makes the patient recovered, while with conservative therapy he has to be on drugs during his life.

[Surgical treatment of tachycardia in children]

Based on the outcomes of surgical treatment in 127 children suffering from tachycardias, three clinical groups were identified: Group 1: an uncomplicated course; Group 2: tachycardias concurrent with congenital heart disease; Group 3: life-threatening tachyarrhythmias. The results of surgical treatment were the following by the groups: Group 1 showed its efficacy in 96.5% and a tachycardial relapse in 3.5%, Group 2 displayed it in 81.0%, deaths in 19.0%, Group 3 exhibited it in 93%, deaths in 7%. In the surgical treatment of the Wolff-Parkinson-White syndrome, the method of choice is epicardial fulguration of the accessory atrioventricular pathway (100% versus 89.4% for the W. Sealy procedure).

[Subendocardial resection in the surgical treatment of ventricular arrhythmia in patients with ischemic heart disease]

The authors have much experience in diagnosing and managing ventricular arrhythmias in patients with coronary heart disease. In most cases, the arrhythmogenic areas are present in the subendocardium and surgeries aimed at improving myocardial revascularization prove to be frequently ineffective in managing arrhythmias. Subendocardial resection proposed by the authors was used in 284 patients. Mortality rates were in 15%, the deaths were mainly due to phenomena of heart failure. Positive results were achieved in 160 (67%) patients. To evaluate the efficacy of the surgical management, the authors consider it advisable to apply programmed endocardial stimulation. The value of pre- and intraoperative mapping is the most important factor that determines the outcome of the surgical management. Subendocardial resection should be regarded as the method of choice just at early stages of the disease in patients with recurrent ventricular tachycardias occurring after acute myocardial infarction.

Relation between ventricular late endocardial activity during intraoperative endocardial mapping and low-amplitude signals within the terminal QRS complex on the signal-averaged surface electrocardiogram

Noninvasive recording of ventricular late potentials and intraoperative endocardial mapping at 36 sites were performed in 24 patients with left ventricular aneurysm and drug-resistant sustained ventricular tachycardia due to coronary artery disease. Their mean age was 55 +/- 8 years. Mean ejection fraction was 28 +/- 12%. For detection of late potentials on the signal-averaged QRS complex, 3 different algorithms were used. Late potentials were found in 54, 67 and 67% of the patients, respectively. In patients with a late potential on the signal-averaged electrocardiogram (ECG), delayed local activation (greater than 40 ms beyond the QRS complex on the intraoperative surface ECG) was recorded at 5.5, 5.5 and 5.6 endocardial sites. In patients without a late potential, this type of delayed local activation was detected at 2.4, 1.1 and 0.9 of 36 endocardial sites, respectively (p less than 0.05; p less than 0.01; p less than 0.002). The mean delay of local endocardial activity was 38, 35 and 37 ms in patients with a late potential on the body surface recording versus 20, 19 and 11 ms, respectively, in patients without a late potential (p less than 0.05; p less than 0.05; p less than 0.002). There was no correlation between the duration or amplitude of the late potential, if present, and the number of endocardial sites exhibiting delayed activity (r = -0.23, r = -0.05, r = 0.21; correlation not significant for each) or the mean duration of the endocardial delayed activity (r = -0.25, r = -0.14, r = -0.07; correlation not significant for each). These results indicate that the presence of late potentials on the signal-averaged surface ECG is related to the mean duration of endocardial late activity as well as to the number of endocardial sites exhibiting a given degree of delayed activation. Thus, it is dependent on the mass of slowly activated tissue. However, a direct conclusion from the duration or the amplitude of a late potential to the amount of delayed activation or the extent of endocardial time delay does not seem possible.

Surgery for control of recurrent life-threatening ventricular tachyarrhythmias within 2 months of myocardial infarction

Twenty-seven patients (mean age 57 +/- 7 years) underwent surgery for control of recurrent drug-refractory ventricular tachyarrhythmias (uniform ventricular tachycardia alone in 9 patients, ventricular tachycardia and ventricular fibrillation in 15 and ventricular fibrillation alone in 3) within 2 months of acute myocardial infarction. The mean number of major arrhythmic episodes per patient was 15 (range 2 to 200) and of drug failures 4 +/- 2. Left ventricular function was severely impaired in the majority (ejection fraction 29%; range 14% to 47%) and 18 patients (66%) had a left ventricular aneurysm. Endocardial resection guided by a combination of endocardial activation mapping during tachycardia and fragmentation mapping during sinus rhythm was performed in all patients. All electrically abnormal left ventricular endocardium was excised. Eight patients (29.6%) died within 30 days of surgery. Death was not related to age, time of surgery after infarction, ventricular function, bypass time or type of arrhythmia. Patients requiring emergency surgery had a higher early postoperative mortality rate than did those undergoing planned surgery (43% versus 15%). During a follow-up period of 32 +/- 20 months, there have been no arrhythmic deaths and only three patients (16%) have required antiarrhythmic drug therapy. When required in the early weeks after infarction, surgery for ventricular arrhythmias offers a high cure rate at a risk related to the patient's preoperative arrhythmia frequency, which in turn relates to the risk of arrhythmic death.

Surgical treatment of the Wolff-Parkinson-White syndrome. Endocardial versus epicardial approach

From 1983 to 1988, 51 patients with the Wolff-Parkinson-White syndrome underwent surgical ablation of an accessory conduction pathway, 25 by the classic endocardial approach and 26 by the epicardial technique supplemented by cryosurgery. In the endocardial and epicardial groups, the accessory pathway was in the left free wall in 22 and 18 patients, respectively, posterior septal in two and seven, and in the right free wall in one patient in each group. There was no early or late death in the endocardial group, and postoperative complications developed in five patients (20%). Pathway ablation was completely successful in 22 patients (88%), preexcitation recurred in two patients (8%), and one had recurrence of supraventricular tachycardia (4%). One of the failures occurred with a posterior septal pathway (50%), and the two others with a left free-wall pathway (9%). With the epicardial technique, there were no early deaths and one late death caused by atherosclerotic coronary artery disease. Five patients (19%) had postoperative complications. The pathway was ablated successfully in 22 patients (85%), preexcitation recurred in three patients (12%), and supraventricular tachycardia remained inducible in another patient despite disappearance of the delta wave. Three of those failures occurred with anterior left free-wall pathways (16%), but only one patient had recurrent supraventricular tachycardia (4%) requiring immediate reoperation, which was successful. In conclusion, although epicardial or endocardial approaches produced similar results, our observations suggest that left free-wall accessory pathways located high anteriorly may be ablated in a more reproducible way with the endocardial technique, whereas the epicardial approach appears easier for posterior septal pathways. We therefore believe that any surgeon beginning such surgery should be aware of the possibilities and limitations of each of the two techniques.

Operative risks of the implantable defibrillator versus endocardial resection

Both map-guided endocardial resection (ER) and the automatic implantable cardioverter defibrillator (AICD) are currently used for surgical treatment of patients who have sustained ventricular tachyarrhythmias. Some authors have preferred AICD implant due to a lower published operative mortality rate. To determine if there is a discrepancy in mortality rates between the two techniques, we analyzed hospital survival in 46 patients undergoing ER and in 44 patients undergoing AICD implantation during the same 3-year period. Two ER patients (4%) died before hospital discharge. Two patients (4%) died after AICD implantation. At predischarge electrophysiologic study five patients (11%) had inducible ventricular tachycardia and received antiarrhythmic drug therapy after ER. In contrast 35 of 42 patients surviving AICD placement received chronic long-term antiarrhythmic therapy (p less than 0.05 compared to ER). Our experience shows that ER and AICD placement may be carried out with similar procedure-related mortality and morbidity rates. Lower operative risks should not be a reason for choosing the AICD over ER for surgical treatment of ventricular tachyarrhythmias. The AICD may actually improve the results of ER by offering an alternative to ventriculotomy in poor-risk surgical candidates.

Extensive endocardial resection for recurrent ventricular tachyarrhythmias

Twenty-two consecutive patients underwent elective map-guided extensive endocardial resection (EER) for recurrent ventricular tachyarrhythmias (VT) of whom 20 were male. The ages ranged from 43 to 74 years (mean 57). All arrhythmias were ischaemic in origin. The mean ejection fraction was 29%. The presenting arrhythmias were ventricular tachycardia in 14, ventricular fibrillation (VF) alone in 1 and ventricular tachycardia and VF in 7. Useful additional intraoperative mapping was obtained in 19 patients. Under cardioplegic arrest, the scarred left (22) and where indicated right (4) ventricular endocardium was extensively resected. Resection of scarred papillary muscles was avoided and where indicated, localised cryoablation was performed: 21/22 had concomitant aneurysmectomy and/or coronary artery bypass grafting. There was 1 (4.5%) operative death. All survivors (95.5%) underwent postoperative electrophysiological studies at around 1 week. None had inducible arrhythmias. There were 3 (13.5%) late cardiac deaths, all due to primary cardiac failure without recurrence of arrhythmia. Of 17 (77%) long-term survivors, 16 (94%) are VT-free on no anti-arrhythmic medication at a mean follow-up of 37.2 months. One developed a new arrhythmia at 1 year which is controlled on medication. EER offers a high rate of success in ablating VT in association with a low operative mortality and good prospect of VT-free long-term survival.

Termination of ventricular tachycardia with epicardial laser photocoagulation: a clinical comparison with patients undergoing successful endocardial photocoagulation alone

Electrical activation-guided laser photocoagulation was used intraoperatively to terminate ventricular tachycardia in patients with ischemic heart disease. During ventricular tachycardia, laser irradiation was delivered to mapped sites with local diastolic activation. In 30 long-term survivors, 85 ventricular tachycardia configurations were terminated by ablation; 72 (84.7%) were terminated by endocardial photocoagulation. Thirteen (15.3%) required epicardial photocoagulation; however, these 13 ventricular tachycardias occurred in 10 (33%) of the 30 patients. An aneurysm was present in 70% of patients with successful endocardial photocoagulation, but in only 10% of patients requiring epicardial photocoagulation for at least one ventricular tachycardia configuration; 90% of all patients requiring epicardial laser photocoagulation had no aneurysm and had either a right or a left circumflex coronary artery-related infarction. In this group, epicardial activation data were similar to those described for ventricular tachycardia with an "endocardial" origin and included 1) delayed potentials during sinus rhythm, 2) presystolic or pandiastolic activation sequences during ventricular tachycardia, and 3) regions of block near the presumed region of reentry during ventricular tachycardia. This study suggests that the critical anatomic substrates supporting reentry in postinfarction ventricular tachycardia may occur at intramural or epicardial sites, particularly in patients with right or circumflex coronary artery-related infarction and no aneurysm.

Treatment of rhythm disorders by endocardial fulguration

The fulguration procedure was originally introduced for the treatment of supraventricular arrhythmias by a pervenous interruption of His bundle conduction. This procedure has been extended to the treatment of almost any cardiac arrhythmia resistant to antiarrhythmic drug therapy. Recent results suggest that ablation could be selectively applied to the site of abnormal conduction. Overall results obtained at the Jean Rostand Hospital are reported for a series of 104 patients ranging in age from 14 to 83 years with atrial, junctional and ventricular tachycardias. The follow-up extends up to 65 months. Clinical efficacy, defined as a control of the arrhythmias by fulguration used alone or in association with drug therapy that was previously ineffective, lead to a success rate ranging from 80 to 85%. Mortality was less than 10% in the worst situation (chronic resistant ventricular tachycardia). Mortality was always related to inappropriate protocols. Therefore, fulguration, which was originally reserved to treat the most difficult cases, is now considered for non-life-threatening but incapacitating arrhythmias. Despite these results the technique is not simple. Fulguration should be performed by groups knowledgeable in electrophysiology and with expertise in high voltage electricity and biophysics.