American heart journal
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American heart journal · Oct 1988
Carotid sinus hypersensitivity in patients with unexplained syncope: clinical, electrophysiologic, and long-term follow-up observations.
To assess the incidence and clinical characteristics of carotid sinus hypersensitivity and the relationship to electrophysiologic findings, 76 patients with unexplained syncope underwent carotid sinus massage during electrophysiologic studies for syncope evaluation. Twenty-one patients (28%) were found to have carotid sinus hypersensitivity. Of these 21 patients, 11 (52%) had coronary artery disease, two (10%) had hypertensive heart disease, and eight (38%) had no organic heart disease. ⋯ Subsequently, this patient has done well after implantation of a pacemaker. These observations suggest that there is a significant incidence of carotid sinus hypersensitivity in patients with unexplained syncope. Permanent pacing appears to be beneficial in selected patients based on clinical and electrophysiologic findings.
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American heart journal · Jul 1988
Comparative StudyBiventricular performance during volume loading in patients with early septic shock, with emphasis on the right ventricle: a combined hemodynamic and radionuclide study.
The cardiac response to a rapid volume infusion was studied in 18 patients with septic shock accompanied by pulmonary hypertension. Right and left ventricular ejection fractions were measured, and right and left ventricular volume indices were calculated from ejection fractions and stroke volumes before and 30 minutes after the start of the infusion. Responders (13 patients) showed an increase in stroke volume index (SVI) as a result of a mean 30% increase in right ventricular end-diastolic volume index (RVEDVI) and a mean 17% increase in left ventricular end-diastolic volume index (LVEDVI) during volume loading. ⋯ At baseline, nonresponders differed from responders as evidenced by a high central venous pressure and RVEDVI but a lower mean arterial pressure: thus, right ventricular coronary perfusion pressure was lower and right ventricular wall stress may have been higher. Mean pulmonary artery pressure did not differ between the groups. Our data suggest that in some patients with septic shock volume loading does not result in increased forward flow because of right ventricular failure associated with pulmonary hypertension and coronary hypotension.
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American heart journal · Jul 1988
Comparative StudyComplicated atherosclerotic lesions: a potential cause of ischemic ventricular arrhythmias in cardiac arrest survivors who do not have inducible ventricular tachycardia?
Sudden cardiac death that is not due to acute myocardial infarction may be due to primary ventricular tachycardia or to an arrhythmia secondary to a transient episode of ischemia. The purpose of this study was to determine if the incidence of complicated coronary lesions, which may be a cause of unstable ischemic syndromes, is increased in survivors of an aborted sudden death, especially those without ventricular tachycardia inducible by programmed ventricular stimulation. Nineteen consecutive survivors of an aborted sudden death not due to an acute infarction who underwent coronary angiography and programmed ventricular stimulation within 3 weeks of the event were matched for age, sex, previous infarction, and severity of coronary artery disease with 38 control patients with stable coronary artery disease. ⋯ However, 6 of the 11 (64%) sudden death patients who did not have inducible ventricular tachycardia had a complicated lesion as compared to only two of the eight (25%) patients with inducible ventricular tachycardia (p = 0.10). Angiograms identified a complicated lesion or functioning myocardium supplied only by collateral vessels as possible sources of transient ischemia in 73% of noninducible sudden death patients and in 25% of inducible sudden death patients (p = 0.04). Thus coronary angiography in cardiac arrest survivors who do not have inducible ventricular tachycardia often suggests a possible mechanism of transient ischemia.(ABSTRACT TRUNCATED AT 250 WORDS)