Search PubMed⌕ Search

Biomedical subjects

R A Bauernfeind

Publications and source records attributed to R A Bauernfeind.

At least 37 records · Page 2Linked to original sources
PubMed1982

Exercise provocable right ventricular outflow tract tachycardia.

During the past 5 years, we have seen six patients who met inclusion criteria of exertional palpitations, reproducible treadmill (TM) provocable ventricular tachycardia (VT), and performance of electrophysiologic (EP) studies including isoproterenol (ISO) infusion. There were five males and one female, aged 15 to 55 years (mean +/- SD, 31 +/- 18 years). Three patients were trained athletes, two patients had mitral valve prolapse, three had enlarged right ventricular (RV) volumes (all trained athletes), and two had no evidence of organic heart disease. TM testing in all patients demonstrated reproducible exercise-provocable VT of at least 20 beats' duration. TM VT was characterized by left bundle branch block pattern ORS morphology and rates of 150 to 230 bpm (186 +/- 30 bpm). EP did not reproduce VT in five of six patients while ISO at a dose of 2 to 4 micrograms/min (2.5 +/- 0.8 micrograms/min) reproduced VT in all patients. ISO VT was characterized by QRS morphology identical to TM VT and rates of 165 to 230 bpm (191 +/- 26 bpm). Endocardial mapping of ISO VT revealed earliest activity in RV outflow tract. Serial TM testing revealed suppression of TM VT in all six patients on propranolol therapy. Responses to class I drugs were variable and less successful. In summary, we describe a group of patients with common clinical, ECG, and electrophysiologic features who may share a common pathophysiology of VT. Possible mechanisms are discussed.

Adolescent↗
PubMed1982

Sequential regional phase mapping of radionuclide gated biventriculograms in patients with sustained ventricular tachycardia: close correlation with electrophysiologic characteristics.

Radionuclide (RNA) gated studies were performed during sinus rhythm and during spontaneous or induced sustained ventricular tachycardia (VT) in six patients with clinical VT. Fourier analysis of time-activity variation was used to calculate a RNA phase value for each pixel in the image. Color coding of each pixel according to its calculated phase resulted in a RNA phase map of the ventricles. The following results were considered to be consistent with the known electrophysiology of VT: (1) the phase map correlated with QRS morphology and axis in most but not all tachycardias; (2) earliest phase usually demonstrated the VT origin to be at the border of the ventricular wall motion abnormality; (3) endocardial mapping (available in one patient) showed close correlation with RNA phase mapping; (4) in three patients with ischemic heart disease, VT with left bundle branch block (LBBB) pattern had earliest LV phase along the septum; and (5) for one patient imaged during two different VT morphologies, the tachycardias had earliest phase at different borders of the same wall motion abnormality with differing progression of phase across the ventricles. RNA phase mapping of VT is feasible and appears to provide data consistent with the electrophysiology of this arrhythmia.

Adult↗
PubMed1982

Electrophysiologic study demonstrating triple antegrade AV nodal pathways in patients with spontaneous and/or induced supraventricular tachycardia.

Ten patients are described with two discrete discontinuities in AV nodal conduction curves suggesting triple antegrade AV nodal pathways. This represents approximately 6% of patients seen in this laboratory with dual AV nodal pathways. Patients ranged in age from 18 to 63 (mean +/- SD, 48 +/- 15 years). Six of the 10 patients had organic heart disease and four did not. The effect of cycle length on triple pathways could be analyzed in 8 of 10 patients who had atrial extrastimulus testing at two or more cycle lengths. Three of these eight patients had triple pathways at all tested cycle lengths. Four patients had triple pathways only at shorter cycle lengths. One patient had triple pathways only at longer cycle lengths. Intact retrograde conduction was demonstrated in seven of ten patients, all of whom had atrial echoes (two patients) or inducible supraventricular tachycardia (SVT) (five patients). Echoes or SVT were induced on the slow pathway is all seven patients, but also on the intermediate pathway in three. However, sustained SVT usually reflected antegrade slow and retrograde fast pathway conduction. In conclusion, triple AV nodal pathways may be demonstrated in occasional patients during atrial extrastimulus testing. Thereby, functional longitudinal dissociation of the AV node is not limited to two pathways.

Adolescent↗
PubMed1982

Electrophysiologic drug testing in prophylaxis of sporadic paroxysmal atrial fibrillation: technique, application, and efficacy in severely symptomatic preexcitation patients.

Electrophysiologic drug testing was performed in nine patients with severely symptomatic sporadic (2 to 13 [mean 4.2] attacks/24 months) paroxysmal atrial fibrillation (PAF). All patients had control inductions of sustained (greater than 30 seconds) AF by high right atrial stimulation, and attempted inductions following serial administration of drugs. Drugs tested were intravenous procainamide (1.0 to 1.5 gm) (five patients), intravenous propranolol (0.1 mg/kg) (three patients), oral quinidine (1.6 to 2.4 gm/day) six patients), oral disopyramide (1.2 to 1.6 gm/day) (four patients), and oral aprindine (100 to 250 mg/day) (four patients). In all patients, one or more drugs prevented induction of sustained AF: procainamide (one patient), quinidine (five patients), disopyramide (four patients), and aprindine (four patients). All patients were treated with drugs which prevented induction of sustained AF and followed for 8 to 40 (mean 24) months. Seven patients tolerated their drugs: six had no AF and one had several short nonsustained attacks. Two patients did not tolerate their drugs: one had paroxysmal palpitation (on decreased aprindine dosage), and one had AF (while off of aprindine). In conclusion, electrophysiologic drug testing is feasible in patients with sporadic PAF. Inability to induce sustained AF following drug administration suggests successful prophylaxis of spontaneous PAF with the same drug.

Administration, Oral↗
PubMed1982

Slowing of paroxysmal tachycardia with loss of functional bundle-branch block.

Electrophysiological studies in a patient with paroxysmal supraventricular tachycardia disclosed anterograde dual atrioventricular nodal pathways, and a concealed left-sided anomalous atrioventricular pathway which was used as the retrograde limb of two circus movement tachycardias. Tachycardia No.1, reflecting anterograde fast pathway conduction, was characterised by functional left bundle-branch block and a stable cycle length of 330 ms. Paroxysmal loss of bundle-branch block resulted in tachycardia No.2, which reflected anterograde slow pathway conduction, and was characterised by narrow QRS and a stable cycle length of 355 ms. Tachycardia No.2 had a longer cycle length than tachycardia No.1 because the increment in AH interval (slow pathway instead of fast pathway condition) more than compensated for the decrement in ventriculoatrial interval (narrow QRS instead of bundle-branch block).

Adult↗
PubMed1982

Twenty-four hour continuous ECG recordings in long-distance runners.

Twenty-four hour ambulatory ECG recordings were performed on 20 male long-distance runners, aged 19 to 28 years, during normal activities other than running. Average, maximum, and minimum waking heart rates, respectively, ranged from 58 to 108 (mean +/- SD, 73 +/- 15), 90 to 164 (120 +/- 19), and 34 to 53 (43 +/- 5) beats/min. Longest waking sinus pauses ranged from 1.35 to 2.55 (1.7 +/- 0.3) seconds. Average, maximum, and minimum sleeping heart rates, respectively, ranged from 38 to 58 (47 +/- 6), 69 to 114 (83 +/- 14), and 31 to 43 (36 +/- 3) beats/min. Longest sleeping sinus pauses ranged from 1.60 to 2.81 (2.0 +/- 0.3) seconds. All 20 runners had atrial premature beats, but only one (5 percent) had more than 100/24 hours. Fourteen runners (70 percent) had ventricular premature beats, but only two (10 percent) had more than 50/24 hours, and none had ventricular couplets or ventricular tachycardia. Eight runners (40 percent) had one or more episodes of type 1 second-degree atrioventricular (A-V) block. Compared with untrained males of similar age, the runners had slower heart rates (by approximately 10 beats/min), longer sinus pauses, and a higher prevalence of A-V block. Runners and untrained males did not differ with respect to prevalence of ventricular premature beats, R on T phenomenon, ventricular couplets, or ventricular tachycardia.

Adult↗
PubMed1981

Arrhythmias documented by 24-hour continuous ambulatory electrocardiographic monitoring in young women without apparent heart disease.

Results are reported of 24-hour ambulatory ECG recordings in 50 young women without apparent heart disease. During waking periods, maximum (sinus) rates ranged from 122 to 189 beats/min (bpm) (153 +/- 14 mean +/- SD) and minimum rates from 40 to 73 bpm (56 +/- 7). During sleeping periods, maximum and minimum rates ranged from 71 to 128 bpm (105 +/- 13) and from 37 to 59 bpm (48 +/- 6), respectively. Thirty-two subjects (64%) had atrial premature beats, with only one subject (2%) having greater than 100 beats/24 hrs. Twenty-seven subjects (54%) had ventricular premature beats, with only three subjects (6%) having greater than 50 beats/24 hrs. One subject (2%) had one three-beat episode of ventricular tachycardia. Two subjects (4%) had transient type I second-degree atrioventricular block.

Adult↗
PubMed1981

Paroxysmal atrial fibrillation in the Wolff-Parkinson-White syndrome.

Eighty-eight patients with preexcitation were studied to determine how 30 patients with documented spontaneous paroxysmal atrial fibrillation differed from 58 patients without this arrhythmia. Inducible reentrant tachycardia was present in 23 (77 percent) of the 30 patients with, versus 28 (48 percent) of the 58 patients without, atrial fibrillation (p less than 0.025). Heart disease was present in 13 (43 percent) of the 30 patients with, versus 15 (26 percent) of the 58 patients without, atrial fibrillation (not significant). Inducible reentrant tachycardia or heart disease, or both, were significant). Inducible reentrant tachycardia or heart disease, or both, were present in 29 (97 percent) of the 30 patients with, versus 34 (59 percent) of the 58 patients without, atrial fibrillation (p less than 0.0005). Of 51 patients with inducible reentrant tachycardia, 23 patients with atrial fibrillation did not differ from 28 patients without this arrhythmia with respect to clinical features and atrial, sinus nodal, or anomalous pathway properties, or cycle length of induced reentrant tachycardia. Spontaneous degeneration of induced reentrant tachycardia to atrial fibrillation was observed in 6 (26 percent) of 23 patients with, versus none of 28 patients without, atrial fibrillation (p less than 0.025). In summary, patients with preexcitation and documented spontaneous paroxysmal atrial fibrillation almost always have inducible reentrant tachycardia or heart disease, or both. It is likely that in many patients with inducible reentrant tachycardia, spontaneously occurring reentrant tachycardia relates to induction of atrial fibrillation. However, it is unclear why some patients with inducible reentrant tachycardia have atrial fibrillation and others do not. In many patients with organic heart disease, atrial fibrillation could relate to hemodynamic changes.

Adolescent↗
PubMed1981

Effects of oral disopyramide phosphate on induction of paroxysmal supraventricular tachycardia.

The effects of oral disopyramide phosphate on laboratory induction of paroxysmal supraventricular tachycardia (PSVT) were studied in 16 patients with clinical PSVT. After control electrophysiologic study to determine the inducibility and mechanism of PSVT, patients were given 200-300 mg (275 +/- 45 mg, mean +/- SD) of disopyramide for three to five doses over 24 hours and were then restudied. All patients had inducible, sustained PSVT during the control study. After disopyramide, PSVT was noninducible in eight patients (50%), including six of nine with atrioventricular nodal reentrance and two of seven with atrioventricular reentrance; inducible but nonsustained in two (12.5%) (both with atrioventricular reentrance); and inducible and sustained in six (37.5%). The benefit of disopyramide seemed predominantly to reflect depression of conduction in the retrograde limb of the circus movements, although effects upon the antegrade limb were also observed. In the eight patients with inducible PSVT before and after disopyramide, tachycardia cycle length increased from 348 +/- 33 to 404 +/- 29 msec (mean +/- SEM) (p less than 0.001). These results suggest that disopyramide would be effective in preventing recurrence of clinical PSVT in selected patients.

Administration, Oral↗
PubMed1981

Significance of the HV interval in 517 patients with chronic bifascicular block.

In January 1975, we reported results of a prospective follow-up study (mean 538 +/- 42 days) of 119 patients with chronic bifascicular block (BFB), and concluded that BFB patients with normal and prolonged HV (NHV and PHV) had a similar incidence of atrioventricular (AV) block and mortality. In this report, we update these findings in 517 patients with a follow-up of 21 days to 9.8 years (mean 3.4 +/- 0.2 years). Three hundred nineteen patients (61%) had NHV and 198 (39%) had PHV (greater than 55 msec). The NHV and PHV groups were similar in regard to age (NHV vs PHV, 61 +/- 1 vs 62 +/- 1 years) and sex (80% male, 20% female vs 82% male and 18% female). The following were more common (p less than 0.05) in patients with PHV (percent of patients with finding in NHV vs PHV groups): angina (18% vs 27%), congestive failure (27% vs 42%), cardiomegaly (48% vs 66%), New York Heart Association functional class II-IV (34% vs 56%), premature ventricular complexes (20% vs 29%), and organic heart disease (OHD) (75% vs 85%). Spontaneous trifascicular block (TFB) developed in two patients (0.6%) with NHV and nine patients (4.5%) with PHV (p less than 0.05). Cumulative 7-year incidence of TFB was 3% with NHV and 12% with PHV (p less than 0.01). Seven-year cumulative cardiovascular mortality was 32% in NHV patients and 57% in PHV patients (p less than 0.005). In conclusion, PHV in patients with chronic BFB was associated with a greater incidence and severity of OHD, and higher total and sudden death mortalities. The risk of spontaneous TFB was small in patients with either NHV or PHV, although it was significantly higher in the latter.

Angina Pectoris↗
PubMed1981

Chronic nonparoxysmal junctional tachycardia.

We describe an adult with chronic (three years' duration) acquired nonparoxysmal junctional tachycardia, a previously undescribed rhythm. Ambulatory monitoring revealed junctional rates ranging from 75 to 110 beats/min. Electrophysiologic studies demonstrated intact atrioventricular and ventriculoatrial conduction with a normal H-V interval (43 msec) and narrow QRS. Underlying sinus node function appeared to be normal (recovery time of 900 msec). Junctional rate increased with administration of atropine and isoproterenol, suggesting that the junctional pacemaker was located in the proximal His bundle. Electrocardiographic and electrophysiologic observations suggested that this case of chronic nonparoxysmal junctional tachycardia was benign, not necessitating therapy.

Aged↗
PubMed1981

Fever caused by hydroxyurea.

Hydroxyurea has been rarely implicated as a cause of drug fever. In this report, we describe a patient who was highly febrile while receiving hydroxyurea for psoriasis. The fever disappeared after discontinuation of therapy with this drug; however, the fever recurred when the patient received hydroxyurea again.

Aspirin↗