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R C Dewey

Publications and source records attributed to R C Dewey.

10 recordsLinked to original sources
PubMed1987

Use of ambulatory electrocardiographic monitoring to identify high-risk patients with congenital complete heart block.

To define the long-term natural history of congenital complete heart block, we followed 27 patients prospectively by means of frequent ambulatory electrocardiographic (ECG) recordings for a mean (+/- SD) of 8 +/- 3 years. During that time, 8 of the 13 patients with a mean daytime heart rate below 50 bpm (Group A) had cardiac complications such as sudden death, syncope, presyncope, or excessive fatigue. Six of the eight patients had additional ECG findings that suggested an instability of the junctional escape mechanism. These findings included nocturnal junctional exit block (three patients), little or no change in the junctional rate with physical activity (three patients), and associated tachyarrhythmias (three patients). None of the 14 patients with a mean daytime heart rate of 50 bpm or more (Group B) had an adverse clinical outcome, and 5 of the 13 patients in Group A also remained well. Among the five patients in stable condition in Group A, three had no evidence of an unstable junctional mechanism. We conclude that patients with a mean daytime junctional rate below 50 bpm and other evidence of an unstable junctional escape mechanism should probably undergo prophylactic pacemaker implantation. Since junctional exit block and tachyarrhythmias sometimes appear first during follow-up, the method of risk stratification employed in this study depends on serial ambulatory ECG recordings.

Adolescent↗
PubMed1984

Relation of ST-segment elevation after healing of acute myocardial infarction to the presence of left ventricular aneurysm.

Persistent ST elevation after healing of myocardial infarction (MI) is often cited as an electrocardiographic sign of left ventricular (LV) aneurysm. This sign is rare in patients with coronary artery disease who have normal or only mildly deranged LV function and is most often associated with QRS patterns indicative of large MI, especially anterior wall MI. To determine whether ST elevation identifies a distinctive abnormality of LV function that might be labeled LV aneurysm, global and regional LV function in 12 patients with QRS patterns of anterior MI and ST elevation were compared with that in 12 patients with similar QRS abnormalities but without ST elevation by means of radionuclide ventriculography. All measured parameters of ventricular function were similar in the 2 groups. ST elevation could not be demonstrated to predict a distinctive abnormality that might be labeled LV aneurysm.

Adult↗
PubMed1983

The electrocardiogram as an index of left ventricular function in coronary heart disease.

To determine the utility of conventional electrocardiographic criteria for the assessment of left ventricular function, we applied pre-determined criteria to the analysis of the ECGs of 171 patients with chronic coronary disease. Eighty patients had no criteria for infarction. Seventeen had a criterion for anterior, 59 a criterion for inferior, three for strict lateral, four for true posterior and eight for combined infarction. Of the 59 with inferior infarction, 25 had QaVF greater than or equal to 0.03 sec. These 25 together with the 25 with anterior or combined infarction constituted a subgroup of 50 patients which included 35 of the 44 (80 percent) of those with an ejection fraction less than 0.50. Among the remaining 121, only nine (7 percent) had a depressed ejection fraction. Thus, the ECG criteria identified correctly 147 (86 percent) patients with regard to the presence or absence of left ventricular dysfunction.

Aged↗
PubMed1980

Impaction fracture of the lumbar vertebrae with dural tear.

The authors described a lumbar spine fracture that is characterized on anteroposterior x-ray views by separation of the pedicular shadows. It is almost invariably associated with posterior interlaminar herniation of the cauda equina through a dorsal dural split, and anterolateral entrapment or amputation of the nerve root. The fracture is unstable and requires internal fixation and fusion at the time of neurolysis. Fractures meeting these criteria should be explored as soon as the patients' condition permits. Myelography is usually unnecessary and may be contraindicated in some cases. The postulated mechanism of injury is hyperextension with vertical impaction and rupture of the ring made up of the lamina, pedicle, and vertebral body. The ring is fractured in several places in a manner similar to that seen in "Jefferson fracture" of C-1. The special anatomical relationships of the thoracolumbar junction and the plane of the lumbar facets are also discussed.

Cauda Equina↗
PubMed1976

Cerebral hemodynamic crisis. Physiology, pathophysiology, and approach to therapy.

The physiology and pathophysiology of the cerebral circulation have been discussed in relation to treatment of the cerebral hemodynamic crisis. Data are presented to show how cerebral vascular resistance, the intracranial compartments, and brain metabolic demand may be manipulated to effect internal decompression and raise local perfusion pressures. It is quite apparent that irreversibility occurs rapidly in cases of complete ischemia and therapeutic success is often limited by this fact. Application of sound therapeutic principles will limit the extent of cellular destruction. Of particular importance to the general surgeon treating the multiply injured patient, is the effect of anesthesia on intracranial pressure in patients with compromised intracranial volume reserve.

Adrenal Cortex Hormones↗
PubMedDate not supplied

Clinical pitfalls in the non-invasive thrombolytic approach to presumed acute myocardial infarction.

A 32 year old patient who presented with a clinical and electrocardiographic picture consistent with an acute inferior myocardial infarction was treated with intravenous streptokinase without the aid of acute angiographic study. Subsequent evaluation revealed the initial diagnosis of acute infarction to be incorrect and the patient was found to have acute viral myopericarditis. No adverse sequelae resulted from the administration of the thrombolytic agent. The potential and reported adverse effects of a non-invasive thrombolytic approach to presumed acute infarction are reviewed and considerations related to clinical decision making in this setting are discussed.

Adult↗