Electrocardiographic analysis of the P waves occurring in a series of 113 normal subjects and 100 patients with specifically defined valvular lesions are reviewed. The former methods of analysis showed a marked lack of specificity. By dividing the P wave in lead V 1 into initial and terminal portions, a measure designated as the P terminal force has been derived. This measure is of value in two respects: (1) it correctly separates normal subjects from those patients with left-sided valvular lesions in 92 per cent of this series and (2) once a given valve lesion is suspected clinically, this measure enables one to make an estimation of the severity of that lesion from the degree of abnormality of the P terminal force at V 1 . The P terminal force does not indicate the type of valvular disease present, nor does it correlate with any one specific hemodynamic measure. The abnormality does appear to be related, within each separate type of valve disease, to the specific hemodynamic abnormality of that type of valvular involvement. The anatomic and electrophysiologic changes that might relate to these P-wave changes are discussed.

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In man, hypocapnia induced by hyperventilation causes a drop in arterial pressure. The calculated peripheral resistance is decreased, indicating a net vasodilatation. The forearm blood flow is markedly increased, and the vascular resistance of the forearm is much reduced. Persons with impaired function of the sympathetic nervous system continue to show these effects. The increase in forearm flow is not prevented by brachial block. These results suggest that hypocapnia acts directly on blood vessels to produce a net over-all vasodilatation and fall in blood pressure, and that this effect is not mediated through the nervous system, as usually supposed.

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SUMMARY Despite a decade of experience with aortocoronary bypass grafting embracing 300,000 or more operations, indications for its use remain controversial. The controversy persists because of a lack of adequate controls with which to compare the clinical course of operated patients; only 1248 have been reported who have been studied in a carefully controlled and random manner.Benefit has been claimed frequently by comparing the course of patients treated surgically with medically treated patients followed the decade before. Such comparisons are not valid in view of the well documented changes in the natural history of coronary artery disease that have been occurring during the last decade.Despite a low operative mortality and rate of graft closure, available data in the literature do not indicate that initial symptomatic improvement necessarily persists, or that myocardial infarctions, arrhythmias, or congestive heart failure will be prevented, or that life will be prolonged in the vast majority of operated patients."It is much easier to write upon a disease than upon a remedy. The former is in the hands of nature and a faithful observer with an eye to tolerable judgment can not fail to delineate a likeness; the latter will ever be subject to the whim, the inaccuracy and the blunder of man."William Withering"