Familial atrioventricular nodal reentry tachycardia

Dual atrioventricular nodal pathways, the substrate responsible for atrioventricular node reentry tachycardia (AVNRT), are thought to be randomly occurring congenital anomalies. This article describes 14 patients in six families, each with two or three first-degree relatives with paroxysmal supraventricular tachycardia. Electrophysiological evidence of dual atrioventricular nodal pathways was established in all 13 patients studied, AVNRT was induced in 12 (92%), and radiofrequency ablation of the slow pathway was curative in all cases. The data suggest a hereditary contribution to the development of atrioventricular nodal pathways and AVNRT. The pattern of inheritance appears to be autosomal dominant.     

Successful radiofrequency catheter ablation of an anteroseptal (superoparaseptal) atrioventricular accessory pathway from the left ventricular outflow tract

This case report describes a patient with Wolff-Parkinson-White syndrome in whom the ECG exhibited a typical pattern of an anteroseptal (superoparaseptal) accessory pathway. Successful radiofrequency catheter ablation was achieved from the septal side of the left ventricular outflow tract. It might be worthwhile to map the left side of the anterior septum if an accessory pathway potential is not appreciable along the tricuspid annulus to avoid the potential complication of AV block in patients with a typical anteroseptal accessory pathway ECG pattern.     

Radical lymph node dissection for melanoma

Background: Therapeutic lymph node dissection for melanoma aims to achieve regional disease control. Radical lymphadenectomy (RLND) can be a difficult procedure associated with significant postoperative morbidity. The aims of the present study were to review regional disease control and morbidity in a series of lymphadenectomies performed within a specialist unit. Methods: The present study involved the analysis of 73 lymphadenectomies in 64 patients, from 1995 to 2001. Results: The overall wound complication rate after inguinal lymphadenectomy (71%) was higher than after axillary lymphadenectomy (47%; P = 0.05). After inguinal lymphadenectomy, the wound infection rate was higher (25.0%vs 5.9%; P = 0.03), delayed wound healing was more frequent (25.0%vs 5.9%; P = 0.03), and the mean time that drain tubes remained in situ was longer (12.5 vs 8.2 days; P = 0.05). There were no significant differences in seroma (46%vs 32%) rates. Lymphoedema was more common after inguinal lymphadenectomy (P < 0.02). Multivariate analysis identified inguinal RLND (P = 0.002) and increasing tumour size (P = 0.045) as predictors of wound morbidity. More patients received postoperative radiotherapy after neck RLND compared to inguinal or axilla RLND (P = 0.03). Six (8%) patients developed local recurrence after lymphadenectomy. At a median follow up of 22 months, 34 (53%) patients have died, from disseminated disease. Conclusions: Radical lymphadenectomy for melanoma is associated with significant morbidity. Inguinal node dissection has a higher rate of complications than axillary dissection. Low local recurrence rates can be achieved, limiting the potential morbidity of uncontrolled regional metastatic disease.     

Self-Conversion of Drug Resistant Ventricular Tachycardia by Rapid Atrial Pacing

A 52-year-old man with recurrent ventricular tachycardia two months post myocardial infarction is described. The tachycardia resulted in low output and heart failure af the lime of presentation. Following elcclrocardioversion of ventricular tachycardia, sinus rhythm would last for only a few seconds, and ventricular tachycardia could not be terminated or prevented by drugs, nor by overdrive pacing. Over a 20-hour period, asynchronous right ventricular pacing at 30/min resulted in repeated random interruption of successive paroxysms of ventricular tachycardia, resulting in maintenance of sinus rhythm about 60 to 70% of the time. This produced marked hemodynamic improvement and a decrease in the frequency of paroxysms of tachycardia which, however, continued to recur once every few days. Despite theirreduced frequency, these paroxysms continued to be resistant to drugs and had to be terminated by cardioversion. At this point it was discovered that rapid a trial pacing was able to terminate the patient's tachycardia reliably and reproducibly. A permanent right atrial externally activated radio frequency pacemaker device was inserted and over the ensuing eighteen-month period the patient self-terminated over fifty discrete episodes of ventricular tachycardia     

Neutrophil function in advanced Hodgkin's disease: Effect of therapy

Whole-blood techniques were used to study neutrophil migration and uptake and killing of Candida in patients with advanced (Stages IIIB and IV) Hodgkin's disease (HD). In order to assess the effect of therapy on neutrophil function, 17 patients were studied either before treatment or on days 1, 8 and 14 of successive cycles of chemotherapy. Neutrophil migration was reduced in 20% of patients, and was largely corrected by normal control plasma. Phagocytosis was normal but killing was reduced in most patients; this reduced killing was not corrected by normal control plasma. Neither chemotherapy nor previous splenectomy had any effect on neutrophil function. It is concluded that defective neutrophil killing, attributable to an intrinsic defect of the cell, is a consistent feature of advanced HD and that a similar defect is present before and after therapy.     

Doppler Ultrasound in Mitral Stenosis

ABSTRACT. In 16 patients with mitral stenosis (MS), alone or in combination with either mitral insufficiency (2 pats.) or aortic valve disease (3 pats.), the mean diastolic pressure gradients across the mitral valve calculated by Doppler ultrasound were significantly correlated to the catheterization data. The average mean pressure drop by Doppler was 11.8 mmHg and by catheterization at rest 16.7 mmHg. A significant correlation between gradients was also found in 5 patients who exercised supine on a bicycle. Atrioventricular pressure half-time (T1/2), i.e. the time during which the pressure drops from the peak value to half of its initial value by the Doppler technique, was significantly correlated to mitral valve area (MVA) determined from catheterization data. Increasing T1/2 reflected decreasing MVA. It is concluded that Doppler ultrasound is a useful method in the evaluation of patients with MS.     

Ocular Pneumoplethysmography in Cardiac Pacing

Varialions in ocular blood flow (OBF) reflect variations in cardiac stroke output very closely. The use of ocular pneumopthysmography (OPG-Gee) for the measurement of OBF is a simple. noninvasive method of assessing the hemodynamics of ventricular versus atrioventricular sequentia pacing.     

Modification by manganese ions and verapamil of the responses of the atrioventricular node to norepinephrine.

In isolated and cross-circulated canine A-V node preparations single injections of Mn2+ (1-30 mumol) and verapamil (0.3-10 nmol) into the posterior septal artery (PSA) caused a dose-dependent increase in the A-V conduction time and, in large doses, produced A-V conduction block. The A-V conduction time increased by Mn2+ and verapamil is resotred by 1-norepinephrine (1-NE) injected into the PSA. The A-V nodal tachycardia induced by 1-NE is suppressed by Mn2+ but not by verapamil. These indicate the following: (1) the slow Ca2+ channel plays an important role in A-V conduction; (2) the positive dromotropic response of the A-V node to 1-NE may have some relations to the Ca2+ channel; (3) the A-V nodal tachycardia induced by 1-NE may be mediated by the Ca2+ channel. Possible causes which produced differences between Mn2+ and verapamil in the effects in antagonizing the 1-NE-induced A-V nodal tachycardia are discussed.     

ASSESSMENT OF THE CORONARY VASODILATOR ACTION OF SK&F 24260 IN THE DOG

1. The effects of SK&F 24260 administered intravenously or intraduodenally on the coronary outflow, coronary arteriovenous oxygen difference (A-V O2), myocardial oxygen consumption (MVO2), systemic blood pressure, heart rate and atrioventricular (AV) conduction time were examined in open-chest dogs. 2. SK&F 24260 in doses of 0.3-10 microgram/kg, i.v., caused a dose-dependent increase in coronary sinus outflow, but the increase was smaller with 30 microgram/kg, i.v., than with 10 microgram/kg, i.v. 3. SK&F 24260 (0.3-30 microgram/kg, i.v.) decreased A-V O2 and MVO2 in a dose-dependent manner. 4. SK&F 24260 (0.3-30 microgram/kg, i.v.) decreased systemic blood pressure and heart rate, and increased AV conduction time. 5. Intraduodenal administration of SK&F 24260 (1 mg/kg) produced almost the same effects on coronary sinus outflow, A-V O2, MVO2, systemic blood pressure, heart rate and AV conduction time as did the intravenous administration of the compound (10 microgram/kg). 6. The property of SK&F 24260 to increase the coronary blood flow and to moderately decrease MVO2, systemic blood pressure and heart rate indicates that this agent is a potential antianginal drug.     

Combinations of selected CNS depressants with d-amphetamine or mazindol on food intake and motor activity of rats.

Amobarbital, diazepam, prochlorperazine and thioridazine were tested alone and in combination with d-amphetamine or mazindol on food consumption and spontaneous motor activity in rats. Of the four depressants tested (1) only amobarbital enhanced the anorexic effects of d-amphetamine and (2) amobarbital, diazepam and prochlorperazine enhanced the hypermotility induced by d-amphetamine. None of the depressants altered the anorexic effect of mazindol but amobarbital and diazepam decreased and prochlorperazine increased the hypermotility induced by mazindol. These differential effects of the CNS depressants suggest that d-amphetamine and mazindol might have different mechanisms of anorexiant or stimulatory action. The data also suggest that, to achieve anorexia with diminished CNS stimulation, combinations of d-amphetamine and any of the tested CNS depressants seem to be precluded. In fact, this desired clinical objective might be achieved with combinations of mazindol and either amobarbital or diazepam.