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Biomedical subjects

J G Selle

Publications and source records attributed to J G Selle.

At least 19 recordsLinked to original sources
PubMed1992

Laser photoablation of ventricular tachycardia: correlation of diastolic activation times and photoablation effects on cycle length and termination--observations supporting a macroreentrant mechanism.

Neodymium:yttrium-aluminum-garnet (YAG) photocoagulation during ventricular tachycardia allows the electrophysiologic effects of the temporal and spatial sequence of energy delivery to be correlated with local activation times. A retrospective analysis was performed of the termination of 19 episodes of ventricular tachycardia for which the local diastolic activation time was known for all successful ablation sites and for 95% of all ablation sites. The mode of termination was compared with that of 26 episodes of spontaneously terminating ventricular tachycardias. Spontaneous terminations occurred without a change in cycle length (54%) or with a 7 +/- 15% change in cycle length over one to three terminal beats (46%). In contrast, laser ablation-induced terminations resulted in a 39 +/- 55% increase in cycle length over nine or more cycles. The effect of attempted laser ablation was compared with the local presystolic activation time and the local activation time expressed as a percent of the diastolic interval (end of QRS complex = 0%, onset of next QRS complex = 100%). With one exception, no tachycardia terminated at ablation sites activating less than -50 ms before the QRS complex. All 8 successful first ablation attempts and 13 of all 19 successful ablations occurred in the 35% to 50% interval of diastolic activation. All successful ablations at sites activating at greater than 50% of the diastolic interval required multiple ablation attempts. Successful ablation was performed from the epicardium in 6 and from the endocardium in 13 episodes of ventricular tachycardia. These results are most consistent with a macroreentrant mechanism with a region of high vulnerability represented by the 35% to 50% interval of diastolic activation.(ABSTRACT TRUNCATED AT 250 WORDS)

Diastole↗
PubMed1992

Surgical treatment of ventricular tachycardia with Nd:YAG laser photocoagulation.

BACKGROUND: Directed surgery for the definitive treatment of drug resistant ventricular tachycardia (VT) due to coronary artery disease carries a significant operative mortality. Surgical failure to cure VT remains a problem, especially in patients without anterior left ventricular myocardial infarcts and aneurysms. A method has been developed in which Nd:YAG laser is used to photocoagulate myocardium responsible for the initiation of VT using a "sequential" approach intended to improve operative results and gain insight into the variable substrates causing VT. METHODS: Under normothermic cardiopulmonary bypass, VT is induced and then extensive endocardial and epicardial mapping performed to localize and characterize that form of VT. Nd:YAG is applied to the areas of myocardium from which that form of VT originates until it disappears and is no longer inducible. Next attempts are made to induce other forms of VT and when successful, mapping and lasing repeated until finally VT is no longer inducible. RESULTS: Fifty-one patients were operated on and have been followed for at least 1 year. Operative mortality in 12 patients with preoperative ejection fractions less than 20% was 41%; in 39 patients with ejection fractions greater than 20% operative mortality was 8%. Eighty-eight percent of the 43 operative survivors are free of recurrent sustained VT at 1 year. There have been no arrhythmic mortalities. In a group of 30 patients evaluated for epicardial VT, 9 of 14 patients with inferior infarcts without left ventricular aneurysms had at least one form of epicardial VT. CONCLUSIONS: Nd:YAG laser photocoagulation of myocardial VT using a sequential approach is a viable method that permits an ongoing study of this entity. Operative mortality remains high in patients with diffusely poor left ventricular function. Epicardial VT is frequent in patients with inferior infarcts and may account for inferior results in these patients when conventional endocardial approaches are used alone.

Adult↗
PubMed1991

"Half and half" woven and knitted Dacron grafts in the aortoiliac and aortofemoral positions: seven and one-half years follow-up.

One-hundred fifty-eight patients received specially manufactured aortoiliac or aortofemoral bifurcated grafts with one limb woven, the other knitted from Dacron. During an observation period ranging from 1,567 to 2,555 days (average 2,130 days) no statistically significant difference was found in either platelet adherence (30 patients studied) or in clinical patency. According to the results of the study, the type of graft (woven or knitted) did not seem to influence either platelet adherence or patency rate in the aortoiliac or aortofemoral positions.

Aged↗
PubMed1991

Surgical division of posterior septal accessory pathways in the Wolff-Parkinson-White syndrome: a new modified approach.

A new modified surgical approach for the division of posterior septal accessory pathways is described. This method incorporates some of the desirable components of previously reported techniques, while eliminating difficult and unreliable aspects of those same techniques. Interestingly this procedure was initially illustrated by Sealy and Mikat in 1983, although it has not been used clinically until now. The recognized intent of this dissection is to totally separate atrial and ventricular structures within the posterior septal space so that all accessory pathways encountered are permanently interrupted.

Atrioventricular Node↗
PubMed1991

Functional role of the epicardium in postinfarction ventricular tachycardia. Observations derived from computerized epicardial activation mapping, entrainment, and epicardial laser photoablation.

BACKGROUND: Conventionally, monomorphic sustained ventricular tachycardia in patients with remote myocardial infarction is believed to originate from the subendocardium. In a previous study, we demonstrated that electrical activation patterns during ventricular tachycardia occasionally suggest a subepicardial rather than subendocardial reentry. METHODS AND RESULTS: This study prospectively evaluated the functional role of the epicardium in postinfarction ventricular tachycardia with complex intraoperative techniques including computerized electrical activation mapping, entrainment, observation of changes in activation pattern during successful epicardial laser photoblation, and histological study. Five of 10 consecutive patients undergoing intraoperative computerized activation mapping had 10 ventricular tachycardia morphologies displaying epicardial diastolic activation These 10 "epicardial" ventricular tachycardias revealed the following global activation patterns: monoregional spread (two), figure-eight activation (five), and circular macroreentry (three). Entrainment of ventricular tachycardia using epicardial stimulation was successfully performed from an area of slow diastolic conduction in four tachycardia morphologies. During entrainment, global activation remained undisturbed with recordings showing a long stimulus to QRS interval, unchanged QRS morphology, and pacing capture of all components of the reentry circuit. Neodymium:yttrium aluminum garnet laser photocoagulation was delivered during ventricular tachycardia to epicardial sites of presumed reentry. Epicardial photoablation terminated five of five figure-eight tachycardias, two of three circular macroreentry tachycardias but not the monoregional tachycardias. Electrophysiological recordings during epicardial laser photocoagulation demonstrated progressive prolongation of ventricular tachycardia cycle length and apparent interruption of the presumed reentrant circuit. Histological evaluation of the reentrant region (three patients) showed a rim of surviving myocardium under the epicardial surface. CONCLUSIONS: This study suggests that 1) chronic postinfarction ventricular tachycardia may result from subepicardial macroreentry, 2) slow conduction within the reentry circuit can be localized by computerized mapping and epicardial entrainment, and 3) ventricular tachycardia interruption by laser photocoagulation results from conduction delay and block within critical elements of the reentrant pathway. Viable subepicardial muscle fibers may constitute the underlying pathology.

Diagnosis, Computer-Assisted↗
PubMed1990

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.

Cardiac Pacing, Artificial↗
PubMed1989

Traumatic tears of the thoracic aorta: improved results using the Bio-Medicus pump.

Traumatic disruption of the descending thoracic aorta is a relatively rare but dramatic injury. Controversy remains regarding the use of shunts during operative repair. Discouraged by our results using the "no shunt" technique, we adopted the recently reported technique using the Bio-Medicus pump for left atrium-femoral artery bypass without heparin sodium. At Charlotte Memorial Hospital and Medical Center, 39 patients were treated for tears of the descending thoracic aorta between January 1979 and October 1988. Eight patients died before repair could be completed. Four patients underwent repair using femorofemoral bypass with 1 death and no instances of paraplegia. Fifteen patients had repair using the no-shunt technique with 4 deaths and three instances of paraplegia. Since January 1986, 12 patients have been treated using the Bio-Medicus heparinless pump with no deaths and no instances of paraplegia. We present our experience to confirm the reports of others regarding the efficacy of this technique. We believe it reduces the morbidity and mortality associated with this serious injury and aids in the hemodynamic management of the patient during aortic clamping.

Adult↗
PubMed1989

The complex posterior septal space in the Wolff-Parkinson-White syndrome. Surgical experience with 47 patients.

Forty-seven consecutive patients with the Wolff-Parkinson-White syndrome due to posterior septal accessory pathways were operated on from August 3, 1983 to March 23, 1989. Seven of these patients had Ebstein's anomaly, another three coronary sinus aneurysms, one a persistent left superior vena cava, and five others complex multiple pathway combinations. Two additional patients required surgery following unsuccessful catheter ablation and one after failed surgery at another institution. Thus nineteen of forty-seven patients (40%) had additional difficulty factors which tend to complicate the operative dissection in this already complex anatomical area. The surgical anatomy of the posterior septal space as well as the essential operative principles and techniques are reviewed. Each of the frequently encountered additional difficulty factors is described with emphasis on the coronary sinus aneurysm, a recently recognized entity.

Adolescent↗
PubMed1988

Rapidly growing nontuberculous mycobacteria: a new enemy of the cardiac surgeon.

A review of atypical mycobacterial infections complicating cardiac operations is presented. Proven sources of infections at different institutions include contaminated porcine valves and municipal water supply, but the mode of transmission in the great majority of patients remains unclear. There are two principal clinical forms of atypical mycobacterial infections after cardiac operations--endocarditis and sternal osteomyelitis. The latter has characteristics resembling tuberculotic "cold abscess." Specialized laboratory testing is necessary to confirm the diagnosis, and surgeons may have to take the initiative to request special microbiological investigation in cases where infection is clinically suspected but routine cultures are reported as "negative." The prognosis for patients who have any atypical mycobacterial infection after a heart operation is severe. Those infected with the strain chelonei and those whose cardiac chambers were entered during operation fare worse. This dim clinical prognosis may be improved by appropriate and aggressive antibiotic and surgical therapy. Awareness of the urgency of special bacteriological studies is the key to successful management.

Anti-Bacterial Agents↗
PubMed1987

Indium 111-labeled platelet deposition in woven and knitted Dacron bifurcated aortic grafts with the same patient as a clinical model.

A study was designed to compare platelet deposition between knitted and woven Dacron grafts in the same patient. Twenty patients received aortoiliac or aortofemoral bifurcated Dacron grafts, each composed of one woven and one double-velour knitted limb. External nuclear graft imaging was carried out after injection of autologous platelets labeled with indium 111. The patients were studied postoperatively in time periods ranging from 6 days to 42 months. Platelet accumulation was almost identical in knitted and woven limbs in all patients. This study appears to indicate that there is no difference in thrombogenicity between knitted and woven bifurcated Dacron grafts in the aortoiliac or aortofemoral positions measured by platelet accumulation.

Aorta, Abdominal↗
PubMed1979

Thoracoabdominal aortic aneurysms. A review and current status.

Surgical management of the thoracoabdominal aortic aneurysm is a formidable undertaking. Presently two fairly distinct operative methods are available. The conventional technique, pioneered by Etheredge, involves replacement of the aneurysm with a synthetic graft and then, step by step, revascularization of the abdominal organs with prosthetic side limbs taken from the primary graft. Individual organ ischemic time is limited to that time required for the performance of each distal side limb anastomosis. The second operative method, first described by Crawford, consists of proximal and distal control of the aneurysm, followed by its incision to simultaneously expose the origin of all four major intra-abdominal arteries. Replacement is then rapidly performed with a tubular Dacron graft including anastomosis of these major intra-abdominal arteries to four elliptical graft incisions, from within the aneurysm. Total operating time is reduced at the expense of prolonged organ ischemia. The conventional method allows for step-by-step intraoperative planning and action, and this technique is accordingly recommended to most surgeons, who have had little experience with this unusual lesion. Our recent successful experience with two cases of extensive thoracoabdominal aortic aneurysms is described as well as a discussion of additional measures which may become useful in certain cases to favor a successful outcome. Finally the problem of potential resultant paraplegia is discussed.

Angiography↗
PubMed1979

Pectus carinatum.

In the mirror of the pertinent literature, we present our experiences gained in 161 operations for pectus carinatum. The Type I (keel chest) deformity is corrected by bilateral resection of the costal cartilages, transverse osteotomy of the sternum, detachment of the xiphoid process, and resection of the lower end of the body of the sternum. The sternum is maintained in its corrected position by utilizing the pulling force of the rectus muscles through the reattached xiphoid and by tacking the pectoralis muscles together in front of the breast bone. Type II (pouter pigeon breast) is handled by double transverse osteotomy, chiseling off the protuberant portion of the strernomanuberial junction, and by supporting the lower sternal body with either the suspended xiphoid process or with Marlex mesh. Limited forms of Type III (asymmetrical or lateral pectus carinatum) are managed with simple resection of the involved cartilages only. If the anomaly is more extensive, bilateral resection of the cartilages and correction of the sternal axis is carried out.

Adolescent↗
PubMed1979

Sinus venosus type of atrial septal defect with partial anomalous pulmonary venous return.

This report describes our method of repairing the sinus venosus type of atrial septal defects. The superior vena cava is compartmentatlized by means of a single double-armed suture. Caval catheters are used as temporary internal shunts, and a vertical U-shaped patch is incorporated into the atriotomy suture line. The experiences with 27 cases are presented.

Adolescent↗
PubMed1979

Pectus carinatum.

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Adolescent↗