PubMed Health⌕ Search

Biomedical subjects

E L Pritchett

Publications and source records attributed to E L Pritchett.

114 records · Page 7Linked to original sources
PubMed1976

Ventriculo-atrial conduction time during reciprocating tachycardia with intermittent bundle-branch block in Wolff-Parkinson-White syndrome.

Records from patients with the Wolff-Parkinson-White syndrome were reviewed with particular emphasis on the occurrence of bundle-branch block aberration during reciprocating tachycardia and the significance of this observation with respect to accessory pathway location. Increase by greater than 25 ms in the ventriculoatrial interval during reciprocating tachycardia with bundle-branch block, when compared to reciprocating tachycardia with normal intraventricular conduction, occurred only with right or left free wall accessory pathways. No patient with a septal accessory pathway proven by epicardial mapping showed a ventriculoatrial interval prolongation greater than 20 ms during bundle-branch block aberration. Measurement of ventriculo-atrial interval during bundle-branch block abe-ration also helped to diagnose accessory pathways AH and HV intervals as well as ventriculo-atrial times, may give midleading information. In one patient increase in cycle length during left bundle-branch block was the result of prolonged HV interval rather than prolonged ventriculo-atrial interval. In another patient cycle length remained the same during bundle-branch block while the ventriculo-atrial interval increased by an increment identical to the decrease in AH interval.

Bundle-Branch Block↗
PubMedDate not supplied

The preexcitation syndromes.

Current methodology permits one to define the functional basis of the preexcitation syndromes with reasonable certainty and to develop a rationale for instituting trials of medical therapy. Future studies will hopefully result in a more exact definition of the anatomic substrates of preexcitation and their relationship to the pathophysiology of the associated syndromes. New antiarrhythmic agents must also be developed to add to the relatively small number of available drugs. Important questions still remain. Should asymptomatic patients with preexcitation be studied? If found to demonstrate potential for malignant arrhythmias, should they be treated prophylactically? The answers to these questions will require study and long-term follow-up of nonhospital referral patients. Surgery offers a feasible therapeutic alternative for patients with life-threatening or disabling arrhythmias but demands a team equipped to perform precise preoperative and intraoperative mapping studies to define the type and location of underlying anatomic substrates.

Arrhythmias, Cardiac↗
PubMedDate not supplied

Effect of verapamil on left ventricular function at rest and during exercise in normal men.

Verapamil is a calcium channel blocking agent used primarily for treatment of arrhythmias and coronary artery disease. It may also depress myocardial contractility. The purpose of this study was to assess the effect of verapamil on left ventricular function. Twelve normal men, 22-29 years of age, were studied at rest and during exercise, with and without verapamil, using first-pass radionuclide angiocardiography. Verapamil was administered by continuous intravenous infusion to produce steady-state blood levels of 106-123 ng/ml. The heart rate, ejection fraction, stroke volume index, and end-diastolic volume index were measured with and without the drug. Verapamil increased the mean resting heart rate from 74 to 78 beats/min (p = 0.001), decreased the mean stroke volume index from 48 to 42 ml/m2 (p = 0.01), and decreased the mean end-diastolic volume index from 77 to 71 ml/m2 (p less than 0.05). No changes in cardiac index, ejection fraction, end-systolic volume index, or peak systolic pressure/end-systolic volume ratio were observed at rest. No differences occurred in exercise hemodynamics. Thus verapamil at therapeutic dose levels did not significantly depress contractility or have other clinically important hemodynamic effects at rest or during exercise in normal subjects.

Adult↗