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Biomedical subjects

L A Biblo

Publications and source records attributed to L A Biblo.

30 records · Page 2Linked to original sources

Multiple monomorphic ventricular tachycardia configurations predict failure of antiarrhythmic drug therapy guided by electrophysiologic study.

OBJECTIVES: The purpose of this study was to determine whether the induction at electrophysiologic study of sustained monomorphic ventricular tachycardias with multiple QRS complex configurations predicted failure of subsequent serial electrophysiologic study guided antiarrhythmic drug testing. BACKGROUND: Ventricular tachycardias with multiple QRS complex configurations are associated with failure of surgical therapy for ventricular tachycardia. As such, the presence of multiple monomorphic QRS complex ventricular tachycardias during electrophysiologic testing may predict failure of subsequent medical therapy. METHODS: Fifty-one consecutive patients with coronary artery disease had reproducible induction of monomorphic ventricular tachycardia during a baseline electrophysiologic study. Each patient then underwent a mean of 1.5 antiarrhythmic drug trials. An antiarrhythmic drug regimen that suppressed induction of ventricular tachycardia was identified in 13 (26%) of the 51 patients. RESULTS: Patients with only one inducible monomorphic QRS complex ventricular tachycardia at baseline study were more likely to have an antiarrhythmic drug regimen identified that suppressed inducible ventricular tachycardia than were patients with multiple monomorphic QRS complex ventricular tachycardias (12[36%] of 33 patients vs. 1 [6%] of 18, p = 0.04). In seven patients with only one induced configuration of ventricular tachycardia, a second monomorphic ventricular tachycardia with a different QRS complex configuration occurred during attempts at pacing termination of the induced ventricular tachycardia. None of these seven patients then had successful drug suppression of inducible ventricular tachycardia. Thus, 12 (46%) of 26 patients with a single monomorphic QRS complex ventricular tachycardia observed at baseline study had successful serial drug testing compared with 1 (4%) of 25 patients with multiple QRS complex ventricular tachycardia configurations (p = 0.002). CONCLUSIONS: The induction or observation of multiple monomorphic QRS complex ventricular tachycardias at baseline electrophysiologic study predicted failure of subsequent serial electrophysiologic study--guided antiarrhythmic drug therapy.

Adult↗

Ventricular arrhythmias in perspective: a current view.

While clinical management of patients with ventricular arrhythmias continues to evolve, some basic principles are generally accepted. First, patients with sustained ventricular tachyarrhythmias (ventricular tachycardia or ventricular fibrillation) require treatment. Second, patients with frequent ventricular ectopy or nonsustained ventricular tachycardia in the absence of underlying structural heart disease do not require treatment except when relief of symptoms is warranted. However, the indication for treatment of patients with frequent ventricular ectopy or nonsustained ventricular tachycardia in the presence of underlying structural heart disease remains uncertain. The concern is that these ventricular arrhythmias may be a precursor for sustained, potentially life-threatening ventricular tachyarrhythmias. Available data suggest that patients with underlying structural heart disease, particularly coronary artery disease and a previous myocardial infarction, who manifest frequent ventricular ectopy or more particularly nonsustained ventricular tachycardia, are at increased risk for sudden cardiac death. However, no studies have demonstrated to date that treatment of these arrhythmias will favorably affect outcome. Data are accumulating to suggest that use of the principles of risk stratification permits identification of patients at very high risk for developing sustained ventricular tachyarrhythmias. Carefully designed clinical trials are required before firm guidelines for the management of these patients can be defined.(ABSTRACT TRUNCATED AT 250 WORDS)

Arrhythmias, Cardiac↗

Selective surgical approach for atrioventricular reentrant tachycardia.

From September 1986 through September 1990, 60 operations were performed in 55 patients (32 male and 23 female; age, 1 to 76 years) for ablation of accessory pathways of atrioventricular reentrant tachycardia; 6 patients had additional cardiac procedures. Between September 1986 and August 1988 the initial surgical approach was exclusively epicardial with adjuvant cryoablation (EPI) in 23 patients (group 1) for a left free wall (LFW) pathway in 11, right free wall (RFW) in 3, posteroseptal (PS) in 7, and anteroseptal in 2. During September 1988 through September 1990, 32 patients (group 2) had the initial surgical approach tailored to the location of the mapped accessory pathway: endocardial approach (ENDO) for LFW in 17 and for juxtanodal pathway in 2, EPI for RFW in 3 and for PS in 9, and combined ENDO and EPI for AS in 1. There was no early or late death in either group. In group 1, 2 patients with LFW pathway had development of recurrent preexcitation in the same compartment requiring ENDO reoperation 10 and 11 months later, 1 with anteroseptal pathway needed immediate ENDO and EPI reoperation, and another with LFW, who required pericardial patch repair of a left atrial tear, had a thromboembolic stroke 2 days later. No serious complications occurred in group 2, but 2 patients with PS required reoperation before discharge for a second accessory pathway in another compartment (1 RFW and 1 LFW). Additionally, 4 patients (2 in each group) had from the beginning ablation of two pathways in different compartments. On complete late follow-up (mean, 28 months) all patients are back to preoperative levels of activity and are free of preexcitation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Strategies in the surgical treatment of malignant ventricular arrhythmias. An 8-year experience.

Introduction of the automatic implantable cardioverter defibrillator (AICD) has dramatically affected the surgical treatment of malignant ventricular tachyarrhythmias. The authors continue to perform electrophysiologically directed subendocardial resection (SER) of left ventricular (LV) scars in selected patients, and we revascularize (CABG) those patients undergoing AICD implantation who have significant myocardial ischemia. In an attempt to define the optimal role of each procedure, this report analyzes our 8-year experience with 348 consecutive patients treated surgically for these arrhythmias (SER since 1983 and AICD since 1986). All patients undergoing SER had organized ventricular tachycardia (VT) as a result of myocardial infarction, and most had LV aneurysms; of those undergoing AICD or AICD/CABG, 60% had VT, 15% had ventricular fibrillation, and 25% had both or were noninducible. The thirty-day mortality rate was 1.5% (3/197) for AICD, 5.4% (5/93) for AICD/CABG, and 8.6% (5/58) for SER; these mortality figures are not significant different. Late deaths in all groups were predominantly due to congestive heart failure, and actuarial survival as well as freedom from sudden death was similar between the groups at 4 years. Recurrent VT occurred in 167 of 282 (59%) of long-term survivors of AICD or AICD/CABG during follow-up and in nine of 53 (17%) of those with SER. Forty-eight per cent of survivors of AICD or AICD/CABG required antiarrhythmic medications, whereas only 11% of those with SER required antiarrhythmics. Long-term survival in each group is much higher than that reported for comparable patients with severe LV dysfunction treated medically. In those patients with organized VT and LV aneurysm who are judged able to survive the procedure, SER offers a high likelihood of cure rather than simple prevention of sudden death.

Actuarial Analysis↗

General evaluation of out-of-hospital sudden cardiac death survivors.

Survivors of out-of-hospital sudden cardiac death may have any of a number of etiologies as the cause. Careful in-hospital evaluation is necessary for providing adequate therapy for such patients. In the great majority of survivors of out-of-hospital sudden cardiac death, such evaluation necessarily includes invasive electrophysiological testing for both diagnostic and therapeutic indications. Given the high incidence of recurrence, effective therapy, based on individualized evaluation, must be found.

Cardiac Catheterization↗

Evolving patterns in the surgical treatment of malignant ventricular tachyarrhythmias.

The advent of the automatic implantable cardioverter defibrillator (AICD), generally viewed as a safe and effective intervention, has in some measure discouraged the use of electrophysiologically directed endocardial resection for intractable ventricular arrhythmias. We reviewed the records of 127 patients undergoing either AICD procedures or resection over a 6-year period. Thirty-day mortality was 5.6% (5/89 patients) for all AICD procedures, 10.7% (3/28) for AICD placement plus coronary artery bypass grafting, and 11.8% (4/34) for resection. These mortality figures are not significantly different. Patients undergoing resection were less likely to require antiarrhythmic agents than patients given an AICD (33% versus 61%). Survival at 2 years was 78% in the resection group and 72% in the AICD group. Survival at 4 years was still 78% in the resection group. Only 1 late sudden death occurred in the AICD group and none in the resection group. We conclude that resection continues to be a valuable alternative, offering a greater overall benefit at only slightly increased risk.

Adolescent↗

Late results with concomitant coronary artery bypass grafting and ICD implantation.

BACKGROUND: To determine the influence of left ventricular function on the long-term survival of patients with coronary artery disease and lethal ventricular arrhythmias, who undergo concomitant coronary artery bypass grafting (CABG) and implantable cardiovertor defibrillator (ICD) implantation, we studied survival in 54 consecutive patients who underwent CABG and ICD implantation. METHODS: Group I consisted of 35 patients with left ventricular ejection fraction (LVEF) < or = 35% (mean 25.3 +/- 5.6) and Group II consisted of 19 patients with LVEF > 35% (mean 47.5 +/- 6.6). The two groups were similar with regards to age, gender, clinical presentation, induced arrhythmias, and the number of grafts placed at the time of surgery. RESULTS: Two in-hospital deaths (3.7%) occurred, both in Group I. During follow-up (42.5 +/- 21.8 months), there were 10 deaths in Group I (1 noncardiac, 1 sudden, and 8 heart failure), and 1 death in Group II (heart failure) (p < 0.04). CONCLUSIONS: Concomitant CABG and ICD implantation can be performed with an acceptable in-hospital mortality, even in patients with poor left ventricular function. Although freedom from sudden cardiac death remains excellent, overall long-term survival is limited by refractory heart failure, especially in those patients with left ventricular dysfunction at the time of surgery.

Adult↗

Endocardial potential mapping from a noncontact nonexpandable catheter: a feasibility study.

In previous studies, we established methodology for reconstructing endocardial potentials, electrograms and isochrones from a non-contact intracavitary probe during a single beat. The probe was too large to be introduced percutaneously. Here we examine the possibility of similar mapping with a small multielectrode catheter that could be introduced percutaneously and does not expand inside the cavity. Cavity geometry and endocardial potentials were recorded in an isolated canine left ventricle. Simulated catheter probes were introduced into the cavity. Probe potentials were computed from the measured endocardial potentials and perturbed to include measurement noise, geometrical errors, and limited electrode density. Endocardial potentials were then reconstructed from the perturbed probe potentials and compared to the actual measured potentials. Of all probes simulated, a 3.0 mm (9F) catheter that assumes a curved geometry (e.g., a J shape) inside the cavity performed best (better than a larger 7.6 mm cylinder simulating an inflatable probe). Without bending, a straight cylindrical probe of the same size (9F, 3.0 mm) did not perform well. Sixty probe electrodes were needed for accurate reconstruction. The J-probe reconstruction was very robust in the presence of noise (10%) and of geometry errors (3 mm shift, 10 degrees rotation). The results demonstrate the feasibility of accurate single-beat endocardial mapping using a 9F percutaneous multielectrode catheter that assumes a J shape in the cavity without the need for expansion (e.g., into a balloon or a "basket"). The robustness of the procedure to noise and geometrical errors suggests its applicability in the clinical EP laboratory and the possibility of determining probe position in vivo using current imaging modalities.

Animals↗