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Biomedical subjects

W Pearl

Publications and source records attributed to W Pearl.

At least 19 recordsLinked to original sources
PubMed1992

Effects of simulated altitude and exercise upon ECGs of young black men.

Twenty-five healthy black men between 17 and 21 years of age were evaluated. Their resting and exercise electrocardiograms were recorded at simulated sea level and at a simulated altitude of 4,000 m. Sea level exercise caused a reduction in the amplitudes of R waves and a lowering of J points. Exercise at a simulated altitude of 4,000 m caused a lowering of the J point in several leads and a reduction of the R wave amplitude in lead aVF. Hypoxia caused a reduction in the amplitudes of the T waves and a lowering of the J points in several leads. These effects of exercise and altitude, to a great extent, eliminated the appearance of "early repolarization," which is very common among young black men.

Adult↗
PubMed1991

Right atrial and pulmonary thromboembolism mimicking unstable angina.

Pulmonary thromboembolism is a potentially fatal disease characterized by a highly variable clinical presentation. Mortality rises dramatically with right atrial thromboembolism. In our case right atrial and pulmonary thromboembolism mimicked unstable angina. A high index of suspicion and early use of echocardiography can lead to the prompt diagnosis and timely treatment of this condition. Although the optimal treatment remains controversial, prompt therapeutic intervention is mandated by an otherwise poor prognosis.

Angina, Unstable↗
PubMed1991

Maximizing the informational content of vectorial data in the electrocardiogram.

Scalar electrocardiograms contain a great deal of vectorial data. The informational content of these data can be maximized by treating each angle as a point on a plane whose distance from the origin is equal to the magnitude of its vector. These points can be resolved into their horizontal and vertical coordinates. The coordinates are linear values and can therefore be subjected to standard statistical methodology.

Adolescent↗
PubMed1990

Self-entwinement of an active fixation pacemaker electrode.

We report a case in which an active fixation atrial lead tip became entwined on the proximal lead body during implantation. It was not possible to disengage the tip or to remove the resultant lead loop atraumatically through the insertion site. Removal of the lead was accomplished using a Dotter intravascular snare inserted via a femoral vein, with subsequent successful implantation of a new lead. This unusual technique-related complication emphasizes the need for meticulous fluoroscopic visualization during lead manipulation.

Aged↗
PubMed1989

Sexual maturity rating: a marker for effects of pubertal maturation on the adolescent electrocardiogram.

The heart is known to participate in the adolescent growth spurt. A peak increase in transverse diameter coincides with peak height velocity during pubertal maturation. The effects of maturation on the adolescent ECG were explored using sexual maturity rating (SMR) as a marker. ECGs were obtained from 751 patients 8 to 20 years of age seen for routine physical examinations. A total of 33 standard ECG measures were analyzed, with subjects separated by sex and SMR. Different trends were seen in boys and girls during the course of maturation for the majority of R and S wave amplitude measurements. Lower mean amplitudes were seen consistently in more mature (SMR 4 and 5) girls than less mature girls and all boys. The clinical implication of these findings is illustrated by analysis of the sum of RV5 and SV2, one of the criteria for left ventricular hypertrophy, by sex and SMR. No significant difference in the sum is noted for boys across five SMR groups. Girls, in contrast, show a steady decrease in the sum with advancing maturation. These trends are not as clearly shown when subjects are grouped by broad chronologic age ranges, as had been the practice in developing current adolescent ECG tables. These findings suggest that development of standard ECG tables in which SMR and sex have been taken into account might enhance interpretation during adolescence.

Adolescent↗
PubMed1988

Stokes-Adams attacks in congenital complete heart block.

Stokes-Adams attacks are a well-known complication of congenital complete heart block. Although they are generally felt to be precipitated by either bradycardia or tachycardia, this is poorly documented. A case is presented in which a 23 month old with congenital complete heart block and an intermittently prolonged QT interval had a Stokes-Adams attack during a spontaneous episode of ventricular tachycardia. The combination of congenital complete heart block and a prolonged QT interval carries a significant risk of ventricular tachycardia.

Adams-Stokes Syndrome↗