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Biomedical subjects

W D Towne

Publications and source records attributed to W D Towne.

At least 19 recordsLinked to original sources
PubMed1979

The HLA antigens and ABO blood groups in an American Black population with mitral valve prolapse.

A total of 42 American Black patients with mitral valve prolapse and 194 healthy individuals of similar ethnic background were tested for the distribution of various HLA antigens and ABO blood groups. The most significant result was an increased frequency of Bw35 in patients (74%) as compared with controls (39%), with a P value of less than 0.0001; the relative risk was 4.45.

ABO Blood-Group System↗
PubMed1978

Tuberculous Addison's disease and thyrotoxicosis.

Addison's disease developed in two patients after they had tuberculosis. Thyrotoxicosis subsequently developed. In both cases, the adrenal glands were calcified, suggesting that Addison's disease was tuberculous in origin. Results of tests for antihyroglobulin, antimicrosomal, and adrenal cortex antibodies were normal. These findings do not suggest an autoimmune basis for the occurrence of the two endocrinopathies. The rarity of the simultaneous occurrence of both disorders suggests it to be fortuitous.

Addison Disease↗
PubMed1978

Proof by catheterization of mitral valvular origin of a systolic click.

A patient with a loud intermittent midsystolic click presented a problem in differential diagnosis between mitral valve prolapse (intracardiac origin of the click) and left pneumothorax (extracardiac origin). External phonocardiography performed at the time of cardiac catheterization revealed that this loud midsystolic click disappeared whenever a catheter was positioned across the mitral valve. It reappeared whenever the catheter was removed from the transmitral position. Selective left ventriculography confirmed the diagnosis of mitral valve prolapse.

Cardiac Catheterization↗
PubMed1978

Infective aneurysm of the left ventricle: angiographic and echocardiographic features.

A 17-year-old man with staphylococcal endocarditis of the mitral valve developed an infective aneurysm of the posterior left ventricular wall. Echocardiography revealed an echo-free space posterior to the posterior left ventricular wall. This echo-free space undoubtedly represented the aneurysmal sac, because it could be temporarily obliterated by injecting saline into it and was no longer detectable following surgical closure of the sac. Thus echocardiography may be helpful in the detection of an infective aneurysm of the left ventricle.

Adolescent↗
PubMed1978

Electrocardiographic changes simulating acute myocardial infarction caused by hyperkalemia: report of a patient with normal coronary arteriograms.

A patient is described with severe diabetic ketoacidosis and hyperkalemia who presented with an ECG resembling an acute anterior wall myocardial infarction. Treatment of hyperkalemia resulted in prompt return of the ECG towards normal. Subsequent work-up including exercise testing and selective coronary arteriography ruled out any significant coronary artery disease suggesting that the ECG changes were probably caused by hyperkalemia. While similar changes have rarely been described in the past, this would appear to be the first such case in whom coronary artery disease was ruled out by a negative exercise testing and coronary arteriography.

Coronary Angiography↗
PubMed1978

Echocardiographic assessment of ventricular performance following induction with two anesthetics.

Echocardiographic studies were made of 20 healthy patients scheduled for minor surgical procedures to determine whether this technique could be used routinely in the operating room and to evaluate the effects of halothane and enflurane on left ventricular performance. Thirteen minutes following induction of anesthesia with halothane in ten patients (mean end-tidal halothane concentration 0.93 per cent), mean arterial blood pressure, left ventricular (LV) diastolic dimension, LV fractional shortening, mean velocity of circumferential fiber shortening and systolic thickening of the posterior LV wall were significantly decreased. LV systolic dimension was increased significantly. These data indicate that halothane caused decreased contractility in the presence of a decreased afterload. Twelve minutes following induction of anesthesia with enflurane in ten patients (mean delivered enflurane concentration 2.4 per cent), mean arterial blood pressure and LV systolic and diastolic dimensions were decreased, while heart rate was increased significantly, indicating that enflurane caused vasodilatation and may have had some depressant effect on contractility. Echocardiography is a non-invasive, safe and relatively rapid method that can be used in the perioperative period to assess cardiac function and to evaluate the effects of pharmacologic agents on the heart.

Adolescent↗
PubMed1978

Effects of gravitational stresses on mitral valve prolapse. I. Changes in auscultatory findings produced by progressive passive head-up tilt.

The effects of passive head-up tilt on systolic time intervals were assessed in 18 patients with mitral valve prolapse. In addition to causing prolongation of the pre-ejection period and shortening of left ventricular ejection time, this circulatory stress led to progressive shortening of the Q to click interval. In 1 patient, a systolic click became audible which had not been heard in the supine posture. In 7 patients the click disappeared during head-up tilt, usually at 60 degrees or 90 degrees. In 2 patients without a murmur while supine, a mid-late systolic murmur appeared with tilt; 1 of these 2 as well as another patient who had a soft late systolic murmur while supine developed loud systolic whoops at greater angles of tile. The correlations between Q to click interval and aortic valve opening to click interval, and both the angle and the sine of the angle of tilt were highly significant.

Adolescent↗
PubMed1978

A new method for measurement of sinoatrial conduction time.

This study describes a new method (NM) for estimation of sinoatrial conduction time (SACT), which utilizes constant atrial pacing (AP) instead of the premature atrial beats (PABs) used in the method reported in 1973 by Strauss et al. The SACTs were obtained by both methods in 20 patients. The SACT by the Strauss method (SM) was calculated as A2A3 minus A1A1. The NM consists of high right AP for a train of eight consecutive beats at rates less than or equal to 10 beats/min faster than the sinus rhythm. The interval between the last paced atrial electrogram (Ap) and the first escape atrial electrogram (A) of sinus origin (Ap-A) was measured along with several post pacing sinus cycles. The SACT by the NM was calculated as follows: SACT = Ap-A minus A1A1. The effect of AP at higher rates was also analyzed. In two patients, the SACT with the SM could not be defined, as all the A2A3 intervals were fully compensatory; with the NM the SACT was 217 and 320 msec. In the remaining 18 patients the SACT was obtainable by both methods. With SM, the SACT ranged 105--452 msec (mean 219 +/- 102 SD) and with the NM it was 85--492 msec (mean 201 +/- 112 SD), and the difference was statistically significant (P = 0.0162). The coefficient of correlation between the two methods was r = 0.97. During AP at faster rates, a rate related increment in Ap-A intervals and also post pacing sinus cycles was noted. This study describes a new and simple method for measurement of SACT in man.

Adult↗
PubMed1978

Differentiation of posterior myocardial infarction from right ventricular hypertrophy and normal anterior loop by echocardiography.

The differentiation of posterobasal myocardial infarction (PMI) from either right ventricular hypertrophy (RVH) or normal subjects displaying an anterior loop (AL) by electrocardiography (ECG) or vectorcardiography (VCG) is difficult. M-mode echocardiography (echo) via the anterior and subxiphoid methods has been helpful in defining cardiac chamber size and wall motion abnormalities. We tested whether this relatively more direct method would better separate these entities compared with the other two techniques. ECG and VCG using established criteria failed to distinguish the three conditions effectively. By echo, distinguishing characteristics were observed in each of the groups. Thus, right ventricular diastolic dimension and wall thickness were significantly increased only in the RVH group, echo dimensions and wall motion were normal in the AL group and the posterior left ventricular systolic thickening response and ejection phase indices were significantly reduced only by the subxiphoid method in the PMI group. To test the specificity of the latter finding, posterior wall motion in three infarction groups (posterior, combined posteroinferior and inferior) were examined and suggested that the target of the subxiphoid beam focuses on a more superior posterobasal left ventricular segment than the anteriorly placed transducer. Echocardiography can differentiate PMI from either RVH or AL more directly than ECG or VCG, and may be of practical clinical importance.

Adult↗
PubMed1978

The mitral knock with atrial fibrillation. A possible source of auscultatory confusion.

A 29-year-old woman with atrial fibrillation and severe rheumatic mitral regurgitation initially had a very loud third heart sound with high-frequency components (mitral knock), as well as with a first heart sound of widely varying intensity. After long diastoles a faint first heart sound was heard, with distinct separation from the third heart sound of the preceding cycle; however, on short cycles the loud and high-pitched third heart sound combined with a loud first heart sound to simulate the combination of a first heart sound with an ejection click. Phonoechocardiographic studies clarified the identity of the transients.

Adult↗
PubMed1977

Conduction system in a patient with Prinzmetal's angina and transient atrioventricular block.

His bundle recordings obtained during and between attacks of Prinzmetal's variant angina and transient atrioventricular (A-V) block were followed by a comprehensive serial section study of the conduction system in a 33 year old woman. Recordings between attacks showed normal A-H and H-V intervals. During an attack there was block proximal to the His bundle recording site. Pathologic studies revealed severe narrowing of the right coronary artery. Arteriolosclerosis of the heart was diffuse. Insignificant changes were found in the approaches to the A-V node and the A-V node itself. Major changes found in the left bundle branch had no counterpart in the electrocardiogram; the discordance in these findings is discussed.

Adolescent↗
PubMed1977

Pulmonary valve vegetations detected with echocardiography.

In a patient with pseudomonas endocarditis a pulmonary regurgitant murmur developed. Sequential echocardiography demonstrated the initial absence of vegetations, the evolution of pulmonary valve vegetations with relapse and finally the apperance of vegetations on all cardiac valves. The findings were confirmed at autopsy. Echocardiography, a useful technique for evaluating mitral, aortic and tricuspid vegetations, can also detect pulmonary valve vegetations.

Adult↗
PubMed1977

Pulmonary edema due to tetrachloroethylene.

A patient with massive exposure to tetrachloroethylene fumes presented with coma and severe pulmonary edema. Sequential blood gases, chest x-rays, and clinical findings showed dramatic improvement with conventional but aggressive management and the patient recovered completely. There was no evidence of permanent renal, hepatic, or central nervous system damage.

Adult↗
PubMed1977

Myocardial infarction associated with thyrotoxicosis.

Myocardial infarction occurs rarely with thyrotoxicosis. A 34-year-old woman with thyrotoxicosis sustained a transmural myocardial infarction and subsequently on cardiac catheterization studies had no significant coronary arterial disease but only residual apical wall akinesia. Thyroid hormone may directly influence myocardial oxygen supply and demand and, by some unknown mechanism exclusive of major coronary arterial blood supply, cause a critical imbalance resulting in angina pectoris and myocardial infarction.

Adult↗