bluuebunny/crossref_metadata_2025 huggingface dataset:
A conductive catheter to improve patient safety during cardiac catheterization.
Authors: Lipton M J , Ream A K , Hyndman B H
Published: June 2012

A 60 Hz current, as small as 20 microamperemeter (rms) is capable of causing ventricular fibrillation when directly applied to the heart. Significant cost and engineering effort has been spent to construct monitoring equipment which satisfies the safety regulations requiring maximum leakage currents below this value. Patients undergoing cardiac catheterization are particularly at risk from electrical hazards, primarily because catheters are made from nonconductive materials. A conductive catheter should allow externally applied currents to leak through its walls before reaching the catheter tip. A new electrically conductive catheter was compared with a standard nonconductive catheter. Five dogs were studied, with 81 attempts to cause fibrillation. Sixty-hertz voltage between the catheter and an external electrode was increased until fibrillation occurred or 130 V was reached. Eight states were studied in randomized sequence: conductive or nonconductive catheter, guidewire or saline-filled and tip touching wall, or free in left ventricle (verified by fluoroscopy and cineangiography). The saline-filled and conductive catheter was safer in that fibrillation never occurred, while fibrillation nearly always occurred with the nonconductive catheter. A conductive guidewire negates the protection of the conductive catheter. The application of conductive catheters could reduce instrumentation costs in laboratories and intensive care units and improve patient safety.
Electrode-catheter arrhythmia induction in the selection and assessment of antiarrhythmic drug therapy for recurrent ventricular tachycardia.
Authors: Mason J W , Winkle R A
Published: June 2012

We performed intracardiac electrophysiologic studies in 33 patients with recurrent ventricular tachycardia. Nineteen patients underwent one, 10 patients two, and four patients three serial electrophysiologic studies. Ventricular tachycardia was successfully induced in 83% of the patients, and pacing methods were successful in terminating tachycardia in 71% of the studies, although pacing-induced acceleration of ventricular tachycardia occurred at least once in 36% of the studies. Seventeen of the 33 patients (52%) required a total of 24 external direct current cardioversions during study. In 21 patients a variety of antiarrhythmic drugs were given I.V. and attempts at ventricular tachycardia induction were repeated to assess prophylactic effects of the drugs. An acutely effective drug or combination of drugs was found in 15 of the patients (71%). Fourteen of the 15 were placed on chronic oral therapy with the effective agent and were followed for an average period of 8.1 months (range one to 33 months). In all 14 patients we could document complete (13 patients) or partial (one patient) long-term prophylaxis against ventricular tachycardia. We conclude that drug efficacy trials in patients with recurrent ventricular tachycardia using intracardiac pacing techniques is a rapid and accurate method of selecting effective long-term antiarrhythmic therapy.
Effect of cholesterol-lowering diet on mortality from coronary heart disease and other causes.
Authors: Turpeinen O
Published: June 2012

International statistics indicate that there is a close correlation between the consumption of saturated fats (dairy fats and meat fats) and the mortality from coronary heart disease (CHD), and this conception has been confirmed by many epidemiological studies. Such studies alone, however, cannot prove the existence of a cause-and-effect relationship between these two variables; dietary intervention trials are needed. The Finnish Mental Hospital Study was such a trial, conducted in two hospitals near Helsinki in 1959--1971. Practically total replacement of dairy fats by vegetable oils in the diets of these hospitals was followed by a substantial reduction in the mortality of men from CHD. Total mortality also appeared to be reduced. As to the causes of death other than CHD, none was significantly influenced by dietary change. This was also true for malignant neoplasms. To alleviate the burden of CHD on public health, many investigators have recommended important changes in the quantity and quality of dietary fats.
Enzymatic indices of myocardial necrosis: influence on short- and long-term prognosis after myocardial infarction.
Authors: Thompson P L , Fletcher E E , Katavatis V
Published: June 2012

The prognostic effect of the peak level of serum creatine kinase (CK) and aspartate transaminase (AST), estimated daily for 3--5 days after acute myocardial infarction, was studied in 560 patients who survived the first day in hospital. In a subgroup of 54 patients, peak enzyme levels correlated well with the cumulated CK release (r = 0.90 with peak CK, r = 0.74 with peak AST), thus reflecting the extent of myocardial necrosis. Total mortality within a year after infarction was not significantly different in the lower three quintiles of peak serum enzyme level, but increased from 15.5% to 27.9% (p less than 0.001) when peak CK level exceeded eight times the upper limit of normal (8 X N) and form 13.1% to 34.8% (p less than 0.001) when peak AST level exceeded five time the upper limit of normal (5 X N). The effect of high enzyme levels was more marked in patients with a prior history of myocardial infarction; mortality increased from 14.7% for first infarctions to 18.2% for recurrent infarctions, with peak CK greater than 8 X N, and from 27.0% for first infarctions to 38.0% for recurrent infarctions with peak CK greater than 8 X N. Early mortality was more significantly affected (p less than 0.0001) than late mortality (p less than 0.05). In hospital survivors, late deaths from cardiac decompensation were three times (p less than 0.05) more frequent in the high enzyme group as in the low enzyme group, but the number of sudden deaths was unaffected. These findings have important implications for studies of reduction of myocardial infarct size.
Factors contributing to altered left ventricular diastolic properties during angina pectoris.
Authors: Mann T , Goldberg S , Mudge G H , Grossman W
Published: June 2012

Mechanisms involved in the altered left ventricular (LV) diastolic properties during angina were studied in 26 patients with coronary artery disease. Angina was induced by rapid atrial pacing and measurements were made at rest and during angina in the immediate post-pacing period. No changes occurred in heart rate (71 +/- 3 to 73 +/- 3 beats/min, NS) or right ventricular (RV) end-diastolic pressure (10 +/- 1 to 11 +/- 1 mm Hg, NS), while significant increases occurred in LV end-diastolic pressure (17 +/- 1 to 30 +/- 1 mm Hg, p less than 0.01), aortic diastolic pressure (74 +/- 3 to 80 +/- 3 mm Hg, p less than 0.01), coronary sinus blood flow (133 +/- 15 to 212 +/- 32 ml/min, p less than 0.01), and the time constant (T) of LV pressure fall in early diastole (43 +/- 2 to 58 +/- 4 msec, p less than 0.01). Despite the rise in arterial pressure, a significant fall was observed in peak negative dP/dt (1961 +/- 106 to 1751 +/- 80 mm Hg/sec, p less than 0.01). Changes in RV end-diastolic pressure do not explain the increased LV end-diastolic pressure during angina. Increased aortic pressure and coronary blood flow may contribute, but the simultaneous fall in peak negative dP/dt and rise in T suggest that impaired ventricular relaxation is an important factor contributing to the previously demonstrated alteration in LV diastolic properties during angina pectoris.
Cellular electrophysiology of human myocardial infarction. 1. Abnormalities of cellular activation.
Authors: Spear J F , Horowitz L N , Hodess A B , MacVaugh H , Moore E N
Published: June 2012

Ventricular tissues were obtained at the time of operation from 12 patients who underwent aneurysmectomy or mitral valve replacement. The electrophysiologic characteristics of these tissues were determined in a tissue bath using microelectrodes. Normal-appearing action potentials were recorded from surviving Purkinje fibers and ventricular muscle cells within infarcted ventricular tissues. Normal muscle action potential recordings from infarcted tissues were similar to action potentials from noninfarcted papillary muscles, except that the duration of the action potential was significantly longer in the former. In other areas slow response potentials were recorded. These action potentials conducted slowly and were eliminated by verapamil. We observed verapamil-sensitive slow response automaticity, but this did not correlate with ventricular tachycardias, present in three patients. Variable amplitude responses arising from normal resting potentials and characterized by stimulus intensity-dependent changes in action potential amplitude were recorded in tissues from two patients. These potentials had many characteristics similar to the slow response, but were not eliminated by verapamil. We also saw inexcitable cells with both normal and abnormal resting potentials. The heterogeneous electrophysiologic characteristics of these tissues provide a likely substrate for arrhythmias and may be the source of the ectopic ventricular rhythms observed in these patients.
Clinicopathologic findings in 52 patients studied by technetium-99m stannous pyrophosphate myocardial scintigraphy.
Authors: Poliner L R , Buja L M , Parkey R W , Bonte F J , Willerson J T
Published: June 2012

Scintigraphic, clinical and pathological findings were correlated in 52 patients studied by technetium-99m stannous pyrophosphate (99mTc-PYP) myocardial scintigraphy before death or surgical resection of myocardium. Fifty-nine clinical events were studied with scintigraphy in the 52 patients; 41 of the 59 were associated with one or more abnormal 99mTc-PYP studies and 18 with normal 99mTc-PYP scintigrams. Myocardial scintigrams were positive in 29 of 31 cases with clinicopathological evidence of a corresponding discrete, grossly obvious acute myocardial infarct, including 16 of 16 transmural myocardial infarcts and 13 of 15 subendocardial infarcts. In 16 of 18 cases, negative myocardial scintigrams correlated with the absence of acute myocardial infarction determined by clinicopathological evidence. In two cases small subendocardial infarcts (less than 3 g) were not detected by 99mTc-PYP myocardial scintigraphy. Of the 12 additional instances of positive 99mTc-PYP myocardial scintigrams, five were associated with clinical unstable angina pectoris and seven were in the category of persistently positive scintigrams, since the scans were obtained 2.5 months or longer after proven or suspected acute myocardial infarcts. In all 12 instances, the positive 99mTc-PYP scintigrams were associated with evidence of multifocal irreversible myocardial damage consisting of myocytolysis, coagulation necrosis and/or fibrosis, and the histological age of the lesions was compatible with acute injury corresponding to the time of scintigraphy. The findings indicate that a positive 99mTc-PYP myocardial scintigram is a sensitive indicator of significant myocardial injury which may occur as confluent coagulation necrosis corresponding to clinical acute myocardial infarction, or as multifocal coagulation necrosis or myocytolysis associated with unstable angina pectoris or recurrent ischemic heart disease, especially after previous infarctions.
Effects of verapamil on myocardial performance in coronary disease.
Authors: Ferlinz J , Easthope J L , Aronow W S
Published: June 2012

Verapamil, a calcium antagonist, has been used extensively for treatment of cardiac arrhythmias. Concern persists, however, that it may seriously depress myocardial function in cardiac patients. To investigate this possibility, 20 patients with coronary artery disease (CAD) but no heart failure were given intravenous verapamil (0.1 mg/kg bolus, followed by 0.005 mg/kg/min infusion), and studied hemodynamically and angiographically. Verapamil markedly lowered mean aortic pressure (94 +/- 17 to 82 +/- 13 mm Hg, p less than 0.0005) and systemic vascular resistance (1413 +/- 429 to 1069 +/- 235 dyn-sec-cm5, p less than 0.0005). Simultaneously, all indices of left ventricular (LV) performance greatly improved: cardiac index rose from 2.8 +/- 0.6 to 3.1 +/- 0.7 1/min/m2 (p less than 0.0005), mean velocity of circumferential fiber shortening increased from 0.85 +/- 0.39 to 0.97 +/- 0.46 circ/sec (p less than 0.01), and ejection fraction improved from 55 +/- 16 to 61 +/- 18% (p less than 0.01). No significant changes were noted in the heart rate before and after verapamil administration, and verapamil did not worsen the extent of LV asynergy in the majority of patients. In patients with CAD, the intrinsic negative inotropic effect of verapamil is of negligible importance because its potent vasodilatory properties more than compensate for any intrinsic decrease in LV contractility, and thereby improve the overall cardiac function.
Detection and exclusion of interatrial shunts by two-dimensional echocardiography and peripheral venous injection.
Authors: Fraker T D , Harris P J , Behar V S , Kisslo J A
Published: June 2012

Two-dimensional echocardiography (2-D echo) was used with peripherally injected contrast material to detect interatrial shunts in 33 patients. Group 1 consisted of 11 patients having classic clinical findings of atrial septal defect. Group 2 consisted of 12 patients with problems requiring that atrial shunting be excluded. Group 3 (control group) consisted of 10 patients undergoing cardiac catheterization for chest pain. Confirmation of the 2-D echo findings was provided by cardiac catheterization in 32 patients and postmortem examination in one. Right-to-left atrial shunts were detected in all 11 patients in group 1, although seven had no right-to-left shunt calculable by oximetry. Four patients in Group 2 had right-to-left atrial shunts. None of the patients in Group 3 had atrial shunts. In the 15 patients with atrial shunts, the degree of right-to-left shunting could be qualitatively assessed as small, moderate, or large. There were no false-negative or false-positive results by contrast 2-D echo.
Improving compliance with therapeutic regimens in hypertensive patients in a community health center.
Authors: Takala J , Niemelä N , Rosti J , Sievers K
Published: June 2012

A 1-year, randomized study was conducted to test the possibility of improving compliance with therapeutic regimens in hypertensives by means of certain simple arrangements. Patients were given written treatment instructions concerning hypertension, a personal blood-pressure follow-up card, and, for those who failed to attend their blood-pressure check-up, an invitation for a new check-up. Using matched pairs, 202 Finnish hypertensives were randomly allocated either to an ordinary or a reorganized treatment group. By means of the latter system, patient compliance could be significantly (p less than 0.01) improved: Only 4% of the patients in this group dropped out of treatment, compared with 19% in the ordinary treatment group. By the end of the year, blood pressure had been lowered by at least 10% in 95% of the patients in the reorganized group and in 78% of those in the ordinary group (p less than 0.01). This was achieved in approximately 60% of cases using chlorthalidone alone.
Alterations in lung volume and pulmonary function in relation to hemodynamic changes in acute myocardial infarction.
Authors: Gray B A , Hyde R W , Hodges M , Yu P N
Published: June 2012

To characterize the changes in lung volumes after acute myocardial infarction (AMI), and the relationship of these changes to other alterations in lung function which correlate with the severity of pulmonary vascular congestion, we made measurements of pulmonary hemodynamics, lung volume, closing volume, frequency dependence of total pulmonary resistance to forced oscillation, and arterial PO2 in 18 subjects with AMI. The most consistent finding was reduced lung volume which correlated with the severity of pulmonary diastolic hypertension. Frequency dependence of resistance showed a small but significant correlation with pulmonary hemodynamics. Closing volume measurements by the resident gas method in nine subjects was not related to hemodynamics. Follow-up studies at the time of hospital discharge revealed a significant return toward normal for arterial PO2, all lung volumes, and total pulmonary resistance at 9 Hz. Based on measurements in healthy subjects, the reduced lung volume after AMI may explain the changes in resistance. In acute and follow-up studies the degree of lung volume reduction and the severity of hypoxemia were strongly correlated.
Quantitative determination of trinitroglycerin in human plasma.
Authors: Wei J Y , Reid P R
Published: June 2012

We developed a simplified method for quantitative measurement of trinitroglycerin in human plasma using hexane extraction and analysis by gas-liquid chromatography with electron-capture detection. This assay was linear from 0.5-60 ng/ml. Sensitivity and reproducibility were +/- 0.5 ng/ml. We used this assay to evaluate the pharmacodynamics of trinitroglycerin in 14 patients. Maximum plasma levels were similar with trinitroglycerin given by constant intravenous infusion (1.6 +/- 0.4 ng/ml (SEM)), transcutaneously (2.3 +/- 0.6 ng/ml), or sublingually (1.6 +/- 0.6 ng/ml). Despite similar levels and hemodynamic responses after intravenous trinitroglycerin, the dose range was wide (37.5-175 microg/min, n = 5), emphasizing the need to individualize therapy. In normal volunteers on no other drugs, the plasma level time course followed changes in heart rate better than blood pressure changes. Use of the trinitroglycerin assay may enhance optimization of trinitroglycerin therapy when administered by different methods.
The characteristic sequence for the onset of contraction in the normal human left ventricle.
Authors: Clayton P D , Bulawa W F , Klausner S C , Urie P M , Marshall H W , Warner H R
Published: June 2012

The sequence for the onset of segmental contraction of the left ventricle was studied in 25 normal patients by analyzing sequential frames obtained at 16.7-msec intervals of right anterior oblique (RAO) ventriculograms by two independent methods. In the first method, we compared the times of onset of contraction of the hemidiameters associated with each of 54 segments with time of onset of contraction of the average of all the hemidiameters for the ventricular contour. In the second method we used a radial coordinate system and determined relative phase relationships by plotting the motion of each of 54 segments against the average motion of all segments. The resulting pattern showed that, on the average, the midregion of the inferior wall began to contract 25 msec before the apex and the midregion of the anterior wall began contraction 18 msec before the apex. In 12 of 25 patients the interior and anterior walls both began to contrast before the apex. In only one of 25 patients did the apex begin to contract first. This sequences of contraction corresponds to the reported sequence of electrical activation for normal human left ventricles.
Ventricular premature contractions: a randomized non-drug intervention trial in normal men.
Authors: DeBacker G , Jacobs D , Prineas R , Crow R , Vilandre J , Kennedy H , Blackburn H
Published: June 2012

The influence of a 6-week intervention on factors thought to be related to ectopic cardiac rhythms was tested in normal men with frequent ventricular premature contractions (VPCs), using a randomized, controlled and partial crossover design. The VPC intervention trial experimental regimen included total abstinence from caffeine and smoking, reduction of alcohol intake, and a physical conditioning program. Effects were studied in detail among 81 healthy men with persistent VPCs. VPCs were measured during standard states of rest, dynamic and isometric exercise and other stresses, and 24-hour ambulatory monitoring. Adherence to the treatment was excellent. The experimental group achieved more than 80% of activities asked of them, and little "contamination" occurred in the control group. VPCs were analyzed according to VPC/min, VPC/man and VPC/total number of heart beats. Moderate changes in VPC rates occurred in both experimental and control groups but no significant group differences were found at rest or during any induction test. This 6-week, multiple-factor "hygienic" intervention program had no significant influence on the frequency or occurrence of VPCs in apparently normal men with persistent and frequent VPCs. Because the mechanisms and the significance of VPCs are different in patients with ischemic heart disease, our approach and methods may be useful for similar trials among cardiac patients of adjunct or non-drug therapy for ectopic rhythms.
Effects of atropine on induction and maintenance of atrioventricular nodal reentrant tachycardia.
Authors: Wu D , Denes P , Bauernfeind R , Dhingra R C , Wyndham C , Rosen K M
Published: June 2012

The electrophysiologic effects of atropine were studied in 14 patients with dual atrioventricular (AV) nodal pathways and recurrent paroxysmal supraventricular tachycardia (PSVT). During PSVT, all patients used a slow pathway (SP) for antegrade and fast pathway (FP) for retrograde conduction. Atropine enhanced both SP antegrade and FP retrograde conduction, shown by a decrease in paced cycle lengths (atrial and ventricular) producing AV and ventriculoatrial block. Five patients had induction of sustained PSVT before and after atropine. Seven patients failed to induce or sustain PSVT before atropine, because of retrograde FP refractoriness. All seven had induction of sustained PSVT after atropine due to facilitation of FP retrograde conduction. Two patients had only single atrial echoes before atropine, reflecting SP antegrade refractoriness. After atropine, sustained PSVT was inducible in one, and nonsustained in the other, PSVT cycle length could be compared in seven patients before and after atropine and decreased from 383 +/- 25 to 336 +/- 17 (p less than 0.05). Thus, in patients with dual AV nodal pathways, atropine facilitated SP antegrade and FP retrograde conduction, shortened cycle length of PSVT and potentiated ability to sustain PSVT.
A mathematical model of the dynamic geometry of the intact left ventricle and its application to clinical data.
Authors: Dumesnil J G , Shoucri R M , Laurenceau J L , Turcot J
Published: June 2012

In this paper we examine the relations that may exist between the geometric variables most frequently used to describe left ventricular contraction. The left ventricle is represented by a thick-walled cylinder contracting both radially and longitudinally. For this model, wall thickening, mid-wall radius shortening and longitudinal axis shorteining can be shown to be uniquely related during contraction, whereas it can be demonstrated that internal radius shortening is not uniquely related to these variables, but is also determined by the specific geometry of the cylinder, expressed in terms of the mid-wall radius-to-wall thickness (R/h) ratio of the cylinder. Detailed analysis of the same variables in 44 normal subjects, 32 patients with aortic stenosis and 54 patients with valvular regurgitation (33 aortic and 21 mitral), strongly suggests that the same relations are also clinically applicable. For instance, ventricular longitudinal axis shortening can be estimated with some accuracy from the standard M-mode echocardiogram. Also, wall thickening can be viewed as the direct reflection of the shortening that occurs in the circumferential and longitudinal directions, whereas internal radius shortening is significantly influenced by the R/h ratio of the ventricle, a consideration which becomes important when analyzing results in patients with left ventricular hypertrophy.
Dopamine beta-hydroxylase and plasma renin activity in patients with low-, normal-, and high-renin essential hypertension.
Authors: Lawton W J , Fitz A , Grant C , Witte D L
Published: June 2012

The relationship of serum dopamine-beta-hydroxylase (DBH), plasma renin activity (PRA) and urinary catecholamines (IU catechols) in various forms of essential hypertension (EHT) (low, normal and high renin) was evaluated. Eighty-four predominantly white, young (37 +/ 8 years (SD)), mildly hypertensive patients (diastolic pressure 93 +/- 4 mm Hg (SD)) continued their regular diet and received no medications. Thirteen patients had low-renin, 64 had normal-renin, and seven had high-renin EHT. DBH, total IU catechols and urinary norepinephrine were not different between these renin subgroups. DBH was significantly lower in all hypertensives (55.6 +/- 36 IU) and in the low-renin subgroup (46 +/- 30 IU) compared with normal subjects (68 +/- 35 IU) (p less than 0.01). However, the DBH range was so broad that an individual DBH value did not distinguish EHT from normals. After a baseline period, patients were randomly assigned to receive chlorthali done 50 mg q.a.m. or placebo in a double-blind study. In the chlorthalidone group 1 month after therapy, the diastolic pressure decreased, PRA increased, and total IU catechols and urinary norepinephrine increased. Serum DBH did not change during diuretic therapy. A significant correlation could not be shown between pretreatment DBH and the changes in PRA and IU catechols before and after diuretics for all treated EHT patients. However, within the normal PRA EHT subgroup receiving chlorthalidone, the one-third of patients with lowest pretreatment DBH levels (n = 10) were compared with the one-third of patients with the highest pretreatment DBH values (n = 10). The lower DBH patients showed significantly less change in PRA (delta PRA = 2.9 +/- 1.8 ng/ml/hr) compared with the higher DBH patients (delta PRA = 8.2 +/- 1.6; P less than 0.05). In some EHT patients, DBH levels may be related to PRA response to diuretic therapy.
Effect of verapamil in infants with paroxysmal supraventricular tachycardia.
Authors: Soler-Soler J , Sagristá-Sauleda J , Cabrera A , Sauleda-Parés J , Iglesias-Berengué J , Permanyer-Miralda G , Roca-Llop J
Published: June 2012

Twenty-nine consecutive spontaneous attacks of paroxysmal supraventricular tachycardia (PSVT) in 14 infants (mean age 4.4 months) were treated with verapamil. No infant had associated heart disease. Verapamil 1-2 mg i.v was administered over 30 seconds. The dosage varied according to the weight of the infant. Within 60 seconds sinus rhythm was obtained in 28 instances (96.5%). No significant complications were observed. The high effectiveness, rapid action and lack of undesirable side effects observed in this series suggest that verapamil is the drug of choice in the treatment of PSVT in infants without underlying heart disease.
Autonomic dysfunction in women with mitral valve prolapse syndrome.
Authors: Gaffney F A , Karlsson E S , Campbell W , Schutte J E , Nixon J V , Willerson J T , Blomqvist C G
Published: June 2012

Autonomic cardiovascular regulation was evaluated in 35 women, 19 with mitral valve prolapse and 16 healthy controls. Heart rate responses to the diving reflex and to phenylephrine infusion were diminished in patients. Noninvasive measures of cardiac output, heart rate, blood pressure, forearm flow and leg volume during lower body negative pressure (LBNP) showed that patients had less lower extremity pooling of blood and had lower forearm conductance. Blood pressures during LBNP rose or remained unchanged despite decreases in cardiac output of 20--25%. These data indicate that mitral valve prolapse patients have an increased venous and arterial vasoconstrictor activity. Cardiac output at rest and echocardiographic indices of contractility were normal. Patients with a history of significant ventricular arrhythmias had higher heart rates and lower forward stroke volumes than the other patients or controls. The combined data demonstrate autonomic dysfunction in women with the mitral valve prolapse syndrome and suggest decreased parasympathetic, increased alpha- and normal beta-adrenergic tone and responsiveness.
Uric acid: a risk factor for coronary heart disease?
Authors: Persky V W , Dyer A R , Idris-Soven E , Stamler J , Shekelle R B , Schoenberger J A , Berkson D M , Lindberg H A
Published: June 2012

The association between serum uric acid and the prevalence of ECG abnormalities was analyzed for 24.997 employed men and women, white and black, age 18--64 years, from the Chicago Heart Association (CHA) Detection Project in Industry. In addition, the relationships between uric acid and 5-year mortality from all causes, from cardiovascular diseases (CVD), and from coronary heart disease (CHD) were analyzed for 7804 white men and women age 45--64 years from this study and 967 white men age 44--63 years from the Chicago People's Gas Company Study. For men, the association between uric acid and the prevalence of ECG abnormalities and with mortality appear to be secondary to associations between uric acid and other risk factors. For women, however, the associations could not be explained by other risk factors.
Complications of coronary arteriography from the Collaborative Study of Coronary Artery Surgery (CASS).
Authors: Davis K , Kennedy J W , Kemp H G , Judkins M P , Gosselin A J , Killip T
Published: June 2012

Data were collected prospectively on 7553 consecutive patients undergoing coronary arteriography. The studies were performed at 13 clinics of the Collaborative Study of Coronary Artery Surgery (CASS) using brachial and femoral techniques. There were eight deaths 0--24 hours and seven deaths 24--48 hours after arteriography (2/1000). There were 15 non-fatal myocardial infarctions (MIs) 0--24 hours and four MIs 24--48 hours after arteriography (2.5/1000). Of 657 cases with left main stenosis greater than or equal to 50%, five died and three had MI. Left main disease increased risk of death by 6.8 times (p less than 0.001). Other factors increasing risk were unstable angina, congestive heart failure, multiple premature ventricular contractions, and hypertension. Of the 1187 patients studied from the brachial artery, six died (0.51%) and five had MIs (0.42%). In 6328 patients studied from the femoral artery, nine died (0.14%) and 14 had MIs (0.22%). The brachial artery technique increased the risk of death 3.6 times compared with the femoral approach (p less than 0.05). This result did not apply when analysis was restricted to laboratories with 80% or more brachial procedures. Risk was not altered by heparin. Thus, a prospective, multicenter analysis of complications reveals low risk of coronary arteriography but significant difference between two techniques.
Measurement of left ventricular ejection fraction by mechanical cross-sectional echocardiography.
Authors: Carr K W , Engler R L , Forsythe J R , Johnson A D , Gosink B
Published: June 2012

Cross-sectional echocardiography is a new noninvasive technique for imaging the heart. We developed a method for using mechanical cross-sectional echocardiograms (sector scans) to determine left ventricular volumes and ejection fraction. Using left ventricular cineangiography as a standard, sector scan ejection fraction correlated better (r = 0.93) than M-mode echocardiography by any of three established methods, and the sector scan regression line did not differ from the line of identity (p greater than 0.33). Interobserver variability for sector scan ejection fraction was 2.3 +/- 1.2% (mean +/- SD). Variation between two studies performed within 24 hours and analyzed by the same observer was 1.4 +/- 1.5%. However, the sector scans consistently underestimated left ventricular end-diastolic volume. We conclude that sector scan echocardiography is more reliable than conventional M-mode technique for estimating left ventricular ejection fraction, but estimation of left ventricular end-diastolic volume is unreliable with the methods currently available.
Familial occurrence of mitral valve prolapse in X-linked muscular dystrophy.
Authors: Biddison J H , Dembo D H , Spalt H , Hayes M G , LeDoux C W
Published: June 2012

A high incidence of mitral valve prolapse (MVP) has been reported in patients with X-linked Duchenne muscular dystrophy. In our study MVP was present in six of 22 Duchenne dystrophy cases (27%) followed in the Maryland General Hospital Muscular Dystrophy Clinic. In addition, seven carriers of Duchenne and X-linked benign (Becker) dystrophy had evidence of MVP. Autosomal dominant transmission of MVP was present in four families. The unusually high prevalence of MVP in families with X-linked muscular dystrophy may have potential value in the recognition of the carrier trait.
Isolated gonococcal pulmonary valve endocarditis: diagnosis by echocardiography.
Authors: Dzindzio B S , Meyer L , Osterholm R , Hopeman A , Woltjen J , Forker A D
Published: June 2012

The perplexing clinical course of a 23-year-old black male with isolated gonococcal pulmonary valvular endocarditis is presented. M-mode echocardiography provided the first clue to the presence of pulmonary valvular vegetations and the proper diagnosis. Since Neisseria gonorrhea appears to have a particular affinity for the pulmonary valve, the presence of isolated pulmonary valvular endocarditis should raise the strong possibility that Neisseria gonorrhea is the offending organism. This case report of pulmonary valvular vegetations detected by echocardiography strongly emphasizes that all four cardiac valves must be visualized in order to rule out the presence of echocardiographically detectable valvular vegetations.
Studies on the Use of Dioxyline Phosphate in the Treatment of Angina Pectoris
Authors: SCOTT RALPH C. , SEIWERT VINCENT J. , FOWLER NOBLE O. , MCGUIRE JOHNSON
Published: June 2012

Dioxyline phosphate, on the basis of pharmacologic studies, appeared to be worthy of trial in the treatment of the anginal syndrome. The patients were studied during a control period and during alternate periods of placebo and dioxyline phosphate administration. Exercise tolerance tests were performed during each of the three periods of observation. The dosage of dioxyline phosphate was 800 mg. per day orally. Five of the 12 patients with angina experienced fewer pains while taking dioxyline phosphate than they did during either the control period or the period of placebo administration. The low incidence of serious side reactions was a conspicuous feature of the study.
Graded Reduction of Arterial Pressure in Man by Means of a Thiophanium Derivative (Ro 2-2222)
Authors: SARNOFF STANLEY J. , GOODALE WALTER T. , SARNOFF L. CHARLOTTE
Published: June 2012

The authors describe the use of a ganglionic blocking agent which acts almost entirely as a peripheral vasodilator with minimal side effects in man. This substance acts almost instantaneously when given intravenously, with the depressor effect quantitatively controlled by regulating the infusion rate without tachyphylaxis over several hours. Depressor effect of the drug disappears 2 to 15 minutes after stopping the infusion and is blocked promptly by intravenous ephedrine, neosynephrine or norepinephrine. The authors discuss its use in the treatment and elucidation of the basic mechanisms of acute pulmonary edema.
Thrombo-embolism in Acute and in Healed Myocardial Infarction
Authors: MILLER R. DREW , JORDAN ROBERT A. , PARKER ROBERT L. , EDWARDS JESSE E.
Published: June 2012

The purpose of this investigation was to study the incidence and location of systemic arterial occlusion and pulmonary embolism in a consecutive series of cases of fatal acute myocardial infarction. Another consecutive series of cases in which healed myocardial infarction was demonstrated at necropsy was similarly studied. In none of the cases included in this study had anticoagulant therapy been employed.

Massive pulmonary embolism was the most frequent fatal thrombo-embolic complication found among the cases of acute myocardial infarction. Cerebral infarction was the most frequent fatal thrombo-embolic complication found among the cases of healed myocardial infarction. Cerebral infarction was the most frequent fatal systemic arterial thrombo-embolic lesion in both groups. Acute splenic and renal infarcts were frequently demonstrated but with one exception appeared to play an incidental role in the clinical course of the patients. Although systemic arterial occlusion was frequently found in association with intracardiac mural thrombi, there were many other cases in which evidence of systemic arterial occlusion was found in the absence of intracardiac mural thrombi. A positive correlation existed between the presence of pulmonary and systemic arterial occlusion and the occurrence of congestive cardiac failure.
On Certain Abnormal Ballistic Complexes: Their Relationships to Other Mechanical and Electrical Events of the Cardiac Cycle
Authors: KUO PETER T. , SCHNABEL TRUMAN G. , KAY CALVIN F.
Published: June 2012

Ballistocardiograms were recorded simultaneously with intra-atrial and intra-aortic pressure curves, heart sounds, electrokymograms and electrocardiograms in patients with various types of heart disease. In several of these subjects, in addition to the usual ballistic waves, abnormal sets of ballistic complexes occurred. In some individuals, one or more of these abnormal ballistic complexes was so prominent that it dominated the entire ballistocardiogram. By correlating the abnormal ballistic waves with other dynamic and electrical events, we have secured information which throws light on the genesis of certain abnormal waves and of the so-called H wave in the ballistocardiogram.
The Effect of Mercurial Diuretics on the Excretion of Water
Authors: CAPPS J. N. , WIGGINS W. S. , AXELROD D. R. , PITTS R. F.
Published: June 2012

In experiments on 11 normal subjects and on three dogs it has been observed that mercurial diuretics do not prevent the stimulation of water absorption and formation of hypertonic urine which characteristically follows the infusion of Pitressin. Furthermore mercurial diuretics only rarely increase urine flow when administered in the course of maximal water diuresis. These two facts are interpreted as meaning that the diuretic agents have no primary effect on the reabsorption of water. Rather, increased urine flow results secondarily from increased elimination of ions.
Studies on the Spread of Excitation through the Ventricular Myocardium
Authors: BURCHELL HOWARD B. , ESSEX HIRAM E. , PRUITT RAYMOND D.
Published: June 2012

The spread of the excitatory process in the ventricular septum of the dog's heart has been studied in the isolated organ perfused by the Langendorff technic. It has been possible to remove large portions of the free wall of the right and left ventricles and explore the septal surfaces under direct vision. The mean excitatory pathway in the muscular mass of the dog's ventricular septum has been demonstrated to be from apex to base. The left side of the septum is activated before the right side, and the apical part of the right side is activated before its base.
Effects of Cardiac Glycosides upon the Electrical Activity of Single Ventricular Fibers of the Frog Heart, and Their Relation to the Digitalis Effect of the Electrocardiogram
Authors: WOODBURY LOWELL A. , HECHT HANS H.
Published: June 2012

Using microelectrodes having an external diameter of less than 1 , µ, potential variations of single cardiac fibers were obtained from frog ventricular muscle in situ. The normal membrane potential consists of a rapid depolarization and slow recovery, the latter occurring in three distinct phases. Digitalis glycosides alter profoundly the slopes of these various phases and drastically shorten the entire period of recovery. The characteristic cardiac action potential is thus converted into a spike which resembles the electrical events recorded for skeletal muscle or nerve. These changes occur independently of mechanical systole which remains essentially unaltered. The deformation of the action potential occurs uniformly throughout the ventricular muscle. They are related to the RS-T segment depression of the surface electrocardiogram which in this instance cannot be explained as being caused by a failure of the diastolic repolarization of the endocardial surface but must be an expression of uniform shortening of the entire process of recovery.
Transient Ventricular Fibrillation
Authors: SCHWARTZ SIDNEY P. , HALLINGER LEONARD , IMPERIALLI ANTHONY
Published: June 2012

Procaine amide was given intravenously to three patients with transient ventricular fibrillation during established auriculoventricular dissociation at a time when they were free from symptoms as well as during the attacks. It was determined that this drug has a transitory slowing effect upon the auricles. It depresses rhythmicity in the auriculoventricular node, prolongs the refractory period of the ventricles, results in intraventricular conduction disturbance and the development of premature beats of the ventricles followed by the various forms of ventricular acceleration leading to ventricular fibrillation. Because of these alterations in heart rhythms, procaine amide is contraindicated in the treatment of such patients.
Hypersensitivity to Mercuhydrin
Authors: WHITMAN JOHN F. , PROUDFIT WILLIAM L.
Published: June 2012

Specific hypersensitivity to the mercurial component of meralluride sodium was induced by a series of intramuscular injections in 12 patients who were being treated for congestive heart failure. Reactions were characterized by fever and systemic symptoms and were precipitated in hypersentitive patients by minute amounts of the drug. No untoward effects resulted from administration of full therapeutic doses of two other mercurial diuretics. Reactions appeared to be modified or inhibited by the action of tripelennamine hydrochloride and British anti-lewisite (BAL); eventual disappearance of the allergic response was demonstrated in two patients.
Acceleration of Blood Coagulation in Acute Myocardial Infarction as Demonstrated by the Heparin Clotting Time; Effect of Dicumarol Therapy
Authors: ROSENTHAL ROBERT L. , WEAVER JOHN C. , BENEDEK AGNES
Published: June 2012

A study of blood coagulation was made on cardiac patients with and without acute myocardial infarction, prior to anticoagulant therapy. The heparin clotting time, an in vitro modification of the heparin tolerance test, was accelerated in 74 per cent (14 out of 19) of the patients with acute myocardial infarction studied within three weeks after the attack. One out of 14 patients without acute myocardial infarction had an accelerated heparin clotting time below 20 minutes, the lower limit of the "normal" range established on the basis of study of over 100 control subjects. The clotting time and platelet count revealed no significant variations. Serial coagulation studies, performed on patients receiving Dicumarol therapy, revealed that the heparin clotting time, which provides a sensitive measure of over-all coagulability, is prolonged as the prothrombin concentration is diminished. The significance of these findings in relation to thromboembolic complications of acute myocardial infarction and anticoagulant therapy is discussed.
The Action of SKF 688A (Phenoxyethyl Derivative of Dibenamine) upon Certain Functions of the Sympathetic Nervous System in Man
Authors: REDISCH WALTER , TEXTER E. CLINTON , HOWARD ROYAL M. , STILLMAN PAUL H. , STEELE J. MURRAY , SASLAW LEONARD
Published: June 2012

A Dibenamine analogue was administered orally to five hypertensive and 10 normotensive subjects over periods from 14 to 21 days. Its adrenergic blocking effect was studied by observing blood pressure, pulse rate, skin temperature of the toes and the pupillary mechanism. Nasal congestion, weakness, listlessness, dizziness, drowsiness and palpitation were persistent sequelae of adrenergic blocking. The drug was found valuable for investigation of autonomous nervous system functions and may hold promise as a therapeutic agent for the treatment of arterial insufficiency and some types of hypertensive subjects.
The Nickerson Ballistocardiogram in Arteriosclerotic Heart Disease with and without Congestive Failure
Authors: JONES RICHARD J.
Published: June 2012

Comparison of ballistocardiograms in patients with arteriosclerotic heart disease with those of normal subjects, young and old, with regard to the various time relationships of the I and J waves, as well as the IJ amplitude, reveals increasingly frequent abnormality in age as compared with youth, in arteriosclerotic heart failure as opposed to heart disease. Certain characteristics of the ballistic pattern in heart failure are noted, and these are modified to some extent by therapy. Serial studies indicate a peak increase in ballistic amplitude with diuresis which may not be sustained.
The Ballistocardiogram in a Free Clinic
Authors: MCGUIRE JOHNSON , HERWITZ GISELA , BRAUNSTEIN JOHN R.
Published: June 2012

Of 240 patients consecutively admitted to the Cardiac Clinic of the Cincinnati General Hospital, and on whom a clinical diagnosis of heart disease was ultimately established, 204 had a ballistocardiogram taken and either an electrocardiogram, a six-foot chest plate or both of the latter two. The ballistocardiogram was evaluated (1) in terms of abnormality of pattern and (2) in degree of deviation from normal initial cardiac force. Frequency of abnormality in the various technics is presented for the group as a whole as well as for several etiologic groups. It is concluded that for a population of this kind the frequency of abnormality in the ballistocardiogram and electrocardiogram is essentially the same, whereas it is somewhat less in the chest plate.
The Origin of the Variations of Body Impedance Occurring during the Cardiac Cycle
Authors: BONJER F. H. , VAN DEN BERG JW. , DIRKEN M. N. J.
Published: June 2012

If the trunk is placed between two electrodes of a high frequency circuit, changes in impedance occur during the cardiac cycle. Experiments are presented which show that these variations do not result from the actual volume changes of the heart, as has been suggested in the literature. The changes in impedance are caused by the rhythmic variations in blood content of the vessels.
An Evaluation of the Ability of Priscoline, Regitine, and Roniacol to Overcome Vasospasm in Normal Man
Authors: GREEN HAROLD D. , GOBEL W. KENNETH , MOORE MICHAEL J. , PRINCE THOMAS C.
Published: June 2012

This paper is a study of the comparative efficacy of Priscoline, Regitine, and Roniacol in relaxing vasospasm in the extremities of normal human subjects. A total of 60 studies were performed on 14 subjects. Severe cutaneous vasospasm was induced by exposure of the lightly clad subject to an environmental temperature of 20 C. for one hour or more. In half the tests the severe vasospasm was reduced to moderate vasospasm by application of heat to the torso of the chilled subjects. The effectiveness of the drugs was tested by giving them by intravenous infusion after the appropriate state of vasospasm had been obtained. The degree of relaxation of vasospasm was estimated from the resulting changes in cutaneous temperature recorded with thermocouples.
Clinical Characteristics of Hypertension Associated with Unilateral Renal Disease
Authors: PERERA GEORGE A. , HAELIG ARTHUR W.
Published: June 2012

A comparison has been made of 20 patients with unilateral renal disease, apparently cured of their hypertension by nephrectomy, and of another group of 20 who showed persistence of elevated blood pressure readings after surgery. Evidence is presented that unilateral renal disease, when it is responsible for hypertension, produces an acute, severe and accelerated process different in many respects from the usual picture of essential hypertension or of chronic bilateral renal disorders. The diagnostic value and the possible bearing of this observation on the mechanisms of renal hypertension are discussed.