Convocation lecture: The QRS complex revisited

Wide QRS Complex Tachycardia

A 71-year-old man with a history of previous myocardial infarction was referred to our hospital for recurrent symptoms of palpitation and syncope. During an episode of palpitations, a 12-lead ECG (Figure 1) was obtained in the emergency room. The ECG shows a wide-QRS complex tachycardia at a rate of 167 bpm. The P waves are positive in lead II (↑) before each QRS complex, and the PR interval is...

A Narrow QRS Complex Tachycardia:

An 80-year-old man underwent an electrophysiologic procedure because of recurrent episodes of supraventricular tachycardia. Episodes of nonsustained narrow QRS complex tachycardia occurred spontaneously after catheter placement. Examples of the onset and termination of an episode of tachycardia are shown in Figures 1 and 2, respectively. What is the mechanism of the tachycardia? What is the lev...

The Pezcoller lecture: cancer cell cycles revisited.

Genetic lesions that disable key regulators of G1 phase progression in mammalian cells are present in most human cancers. Mitogen-dependent, cyclin D-dependent kinases (cdk4 and cdk6) phosphorylate the retinoblastoma (Rb) tumor suppressor protein, helping to cancel its growth-inhibitory effects and enabling E2F transcription factors to activate genes required for entry into the DNA synthetic ph...

U.G. Convocation Address

Unusual QRS deflections--is this a ratable finding?--Revisited.

This 33 year old man applied for insurance and this electrocardiogram was submitted. A tracing taken three years before was the same. This unusual electrocardiogram was brought to my attention by Dr. William J. Baker, Vice President and Medical Director of Monarch Life Insurance Co. There is no history of any medical difficulties. There were no murmurs heard, cardiac catheterization was done 8/...