bluuebunny/crossref_metadata_2025 huggingface dataset:
The Use of Apexcardiography in the Assessment of Left Ventricular Diastolic Pressure
Authors: VOIGT GUSTAV C. , FRIESINGER GOTTLIEB C.
Published: June 2012

A total of 58 observations of simultaneous left ventricular pressure and apex-cardiograms (ACG) was made on 18 patients. An
a
wave percentage amplitude (aWPA) of greater than 15% of the total deflection of the ACG indicated an increase in left ventricular end-diastolic pressure (LVEDP). In 12 observations on six patients, an aWPA of less than 15% was associated with a high LVEDP. Patients with high LVEDP and aWPA of less than 15% had a high early left ventricular diastolic pressure with further rise in pressure prior to atrial contraction. These patients had small LV
a
waves ("atrial kick"). The aWPA of the ACG correlated better with the magnitude of the LV
a
wave than the absolute level of LVEDP in all patients. Correlation was good between changes in aWPA and changes in LVEDP in individual patients; but the ACG as an indirect means of evaluating left ventricular function is limited by the fact that elevations in LVEDP can exist in the presence of a normal aWPA. The ACG is a complex tracing reflecting not only intracardiac pressures, but changes in left ventricular volume, compliance, position, and perhaps left atrial function as well.
Ventriculo-atrial Conduction in Man
Authors: GOLDREYER BRUCE N. , BIGGER J. THOMAS
Published: June 2012

Transvenous electrodes were placed in the right atrium and ventricle of 50 patients with heart disease and arrhythmias. The ventricles were paced at several rates, each in excess of the sino-atrial rate. An atrial electrogram and surface electrocardiogram were recorded simultaneously in each patient; utilizing strict criteria, the incidence with which 1:1 ventriculo-atrial conduction (VAC) could be elicited in these patients was assessed. These patients were divided into two groups-26 patients with normal A-V conduction comprised group 1, and 24 patients with prolonged A-V conduction, group 2. VAC was demonstrated in 89% of group 1 patients but in only 8% of the group 2 patients. The difference in the incidence of 1:1 VAC between the two groups was statistically significant (
P
< 0.01). The presence or absence of 1:1 VAC could not be related to type of heart disease, medication, presence of acute myocardial infarction, or presence of intraventricular conduction defect.

Altering the paced ventricular rate or introducing stimulated ventricular premature depolarization in group 1 patients could produce any degree of VAC impairment. During such maneuvers, ventricular reciprocal beats (ventricular echoes) and ventricular reciprocal rhythms were observed.
Changing Hemodynamics in Patients with Transposition of the Great Arteries
Authors: PLAUTH WILLIAM H. , NADAS ALEXANDER S. , BERNHARD WILLIAM F. , FYLER DONALD C.
Published: June 2012

Follow-up cardiac catheterizations were carried out on 65 patients with transposition of the great arteries. Patent ductus arteriosus (PDA) was a significant problem in this group only when closure resulted in a precipitous drop in arterial oxygen saturation. Spontaneous closure of ventricular septal defects (VSD) occurred in approximately 20% of patients while natural or surgically created atrial septal defects (ASD) tended to persist. Pulmonary stenosis (PS) was found in 28% of patients with an intact ventricular septum and 50% of those with VSD. Pulmonary artery hypertension (PAH) or pulmonary vascular obstruction (PVO) or both, were present in about half of the patients with an intact ventricular septum and all the infants with a large VSD without pulmonary artery banding or pulmonic stenosis (PS). PS, usually but not invariably, tended to protect the pulmonary vasculature.
Continuous Murmur Due to the Combination of Rheumatic Mitral Stenosis and a Rare Type of Anomalous Pulmonary Venous Drainage
Authors: HALPERN B. L. , MURRAY G. C. , CONTI C. R. , HUMPHRIES J. O. , GOTT V. L.
Published: June 2012

A patient is described in whom a continuous murmur was caused by the combination of rheumatic mitral stenosis and a rare form of partial anomalous pulmonary venous drainage. In this case, the left superior pulmonary vein drained into the left atrium and also into a large anomalous vein which then drained to the right atrium via the innominate vein and superior vena cava. At surgery, mitral commissurotomy and then ligation of the anomalous vein were performed with a good result; the continuous murmur was no longer audible after operation. The embryology, physiology, auscultatory findings and surgical consideration are discussed.
Relationship of the Pulmonary Artery End-Diastolic Pressure to the Left Ventricular End-Diastolic and Mean Filling Pressures in Patients With and Without Left Ventricular Dysfunction
Authors: FALICOV RAUL E. , RESNEKOV LEON
Published: June 2012

The relationship of the left ventricular end-diastolic pressure (LVEDP) and the pulmonary arterial "wedge" mean pressure (PAWMP) to the pulmonary artery end-diastolic pressure (PAEDP) was investigated by cardiac catheterization in 71 subjects. Pressure records were obtained simultaneously or immediately consecutively. In 15 subjects with normal LV function (LVEDP, 4 to 12 mm Hg) PAEDP was within 3 mm Hg of LVEDP (r = 0.70,
P
< 0.01) and within 3 mm Hg of PAWMP (r = 0.69,
P
< 0.01) in every instance.

In 56 patients with LV dysfunction (LVEDP, 12 to 55 mm Hg), PAEDP was lower than LVEDP in 42, equal to LVEDP in six, and higher than the LVEDP in eight, who were in atrial fibrillation or had increased pulmonary vascular resistance (PVR). PAEDP correlated closely with PAWMP (r = 0.92,
P
< 0.001).

In 30 patients with LV dysfunction in sinus rhythm, an
a
wave was identified in the PA pressure tracing (PA
a
) prior to systole which coincided in time and magnitude to the PAW
a
wave and was considered to represent retrograde transmission of the left atrial contraction wave. The PA
a
pressure was within 5 mm Hg of the LVEDP (r = 0.94,
P
< 0.001) in all except four patients, two of whom had elevated PVR.

Thus, in the presence of LV dysfunction and elevated LVEDP, PAEDP correlated well with PAWMP, but failed to represent LVEDP accurately, while PA
a
wave pressure closely reflected LVEDP except when PVR was markedly increased.
The Effect of Ischemia and Alterations of Heart Rate on Myocardial Potassium Balance in Man
Authors: PARKER J. O. , CHIONG M. A. , WEST R. O. , CASE R. B.
Published: June 2012

Myocardial electrolyte balance and lactate metabolism were studied in 30 patients before, during, and after a period of atrial pacing utilizing a continuous automated sampling technic with simultaneous electrocardiographic and hemodynamic observations. Eight patients with coronary artery disease who had no symptoms during pacing and four normal subjects demonstrated myocardial potassium loss but no abnormalities in lactate metabolism, the electrocardiogram, and hemodynamics during pacing. Myocardial potassium loss was correlated with increments in heart rate and was followed by potassium uptake during the post-pacing period. Eighteen subjects developed angina during pacing associated with hemodynamic and electrocardiographic abnormalities. This ischemic group showed significantly greater myocardial potassium loss during pacing than the non-ischemic group, and this was closely associated with myocardial lactate production at a ratio of 1 mEq of potassium being lost for each 2 millimoles of lactate produced. Increased acidity of coronary sinus blood also accompanied potassium loss during ischemia. No significant changes were seen in sodium balance in either group during the study.
Effects of Inspiration, Expiration, and Apnea upon Pacemaking and Block in Atrial Fibrillation
Authors: URBACH JOHN R. , GRAUMAN JACOB J. , STRAUS SANDOR H.
Published: June 2012

The effects of inspiration, expiration, and apnea on A-V transmission system block and on A-V junctional and idioventricular pacemakers were studied in 53 examinations on 29 patients with atrial fibrillation. The severity of block and the location, prevalence, and firing frequency of subsidiary pacemakers were measured separately in each phase of respiration and compared by quantitative methods. In most patients, apnea increased the severity of A-V block, the prevalence of A-V junctional escape and ventricular automaticity but reduced the prevalence of A-V junctional tachycardia. The firing frequency of the subsidiary pacemakers was not affected. Occasionally apnea shortened the coupling interval of premature ventricular contractions. Cheyne-Stokes respiration markedly accentuated the effects of apnea and often produced bursts of ventricular tachycardia in patients who had only isolated ventricular ectopic beats during regular respiration. The data indicate that intermittent respiration has deleterious effects upon cardiac activity and should be corrected whenever possible.
Changes in Plasma and Extracellular Fluid Volumes in Patients with Essential Hypertension During Long-Term Treatment with Hydrochlorothiazide
Authors: LETH ARNE
Published: June 2012

In 13 untreated patients with essential hypertension, the plasma volume (T-1824) and the extracellular fluid volume (
82
Br
-
distribution space) were determined three times. During treatment with 50 to 100 mg of hydrochlorothiazide daily, determinations of plasma volume and extracellular fluid volume were repeated after treatment for 1 mo (13 patients), 2 mo (13 patients), 4 mo (eight patients), and 6 mo ( seven patients). In all cases the average plasma and extracellular fluid volumes were reduced compared with the averages of three control values. The plasma volume was significantly reduced at the 5% level after treatment for 1, 2, and 4 mo.

Corresponding studies from the literature have been reviewed and, on the basis of these studies and our own results, it is concluded that thiazides have a volume-depleting effect which is continued during long-term treatment of patients with essential hypertension.
Hemodynamic Effects of Catecholamine Stimulation in Constrictive Pericarditis
Authors: NAKHJAVAN FRED K. , GOLDBERG HARRY
Published: June 2012

Cardiac hemodynamic studies during control resting state and isoproterenol infusion were performed on five patients with constrictive pericarditis. During isoproterenol infusion, stroke volume increased by 60%, while there was no significant change in pulmonary wedge and right atrial mean pressures. The relatively fixed filling pressure is the indirect evidence of fixed diastolic size of the heart. However, the fixed cardiac size in diastole per se does not necessarily indicate hindrance to filling of the heart unless the limits of diastolic size of the heart are reached. It is concluded that during the supine resting state, when the influence of catecholamines is minimal, systolic emptying of ventricles is hindered. The systolic hindrance is, however, overcome by strong positive inotropic stimulation.
Regulation of Arterial Pressure in the Anephric State
Authors: COLEMAN THOMAS G. , BOWER JOHN D. , LANGFORD HERBERT G. , GUYTON ARTHUR C.
Published: June 2012

Three anephric patients were studied during sequential periods of normal hydration and overhydration. The increase in arterial pressure caused by the overhydration (+7% of body weight) was associated with an increase in peripheral resistance (+21.1%,
P
< 0.01). The elevation of peripheral resistance was preceded by an increased cardiac output (+22.3%,
P
< 0.02) which then fell part way to control levels (+13.2%,
P
< 0.05). Return to normal hydration resulted in return of all variables to control levels. The fall in peripheral resistance was preceded by a transient fall in cardiac output to below control levels (—5.6%, not significant). With both normal and elevated pressures, plasma renin activity levels were low, and sensitivity to angiotensin infusion was greater than normal. Long-term autoregulation of blood flow is suggested as an important factor in the observed sequence of events.
Risk Factors and Prevalence of Coronary Heart Disease in Puerto Rico
Authors: GARCÍA-PALMIERI MARIO R. , COSTAS RAÚL , CRUZ-VIDAL MERCEDES , CORTÉS-ALICEA MARCELINO , COLÓN ANGEL A. , FELIBERTI MANUEL , AYALA ANGEL M. , PATTERNE DOLORES , SOBRINO RAFAEL , TORRES RAQUEL , NAZARIO EMILIO
Published: June 2012

In spite of an apparently increasing mortality rate from coronary heart disease in Puerto Rico, the age-specific mortality rate from this illness is considerably lower in the island than in the U. S. mainland. Examination of 9,814 Puerto Rican urban and rural men in the 45 to 64-year age group revealed sizable and statistically significant differences in monthly income, cigarette smoking, ingestion of fats, blood pressure, heart rate, relative weight, serum cholesterol, serum glycerides, prevalence of diabetes, and prevalence of hypertension (lower in rural dwellers), and also in vital capacity, consumption of calories per unit body weight, and physical activity (higher in rural area). No urban-rural difference in coronary heart disease prevalence was found, but the prevalence of definite myocardial infarction, established on basis of electrocardiographic criteria alone, was significantly higher in the 45 to 54-year urban group. Follow-up of this population to study incidence of disease and the influence of the various factors upon the development of disease is being conducted.
Hemodynamic Changes Following Correction of Severe Aortic Stenosis Using the Cutter-Smeloff Prosthesis
Authors: LEE SIMON J. K. , HARAPHONGSE M. , CALLAGHAN J. C. , ROSSALL R. E. , FRASER R. S.
Published: June 2012

Twelve patients with pure or dominant stenosis were studied before and after aortic valve replacement (Cutter-Smeloff). The changes in cardiac output and A-V O
2
difference were small and insignificant, but exercise stroke volume increased from 72 to 96 ml after the surgery. The aortic peak systolic gradient was 92 ± 29 mm Hg before and 4 ± 9.8 mm Hg after surgery.

The PA wedge pressure, taken as a measure of the LV diastolic pressure, decreased from 18 mm Hg to 12 mm Hg at rest and 30 mm Hg to 16 mm Hg on exercise. The PA pressures also decreased from 37/18 (mean, 26) to 28/11 (17) mm Hg at rest, and 61/31 (43) to 41/17 (27) mm Hg on exercise, but the PA and PA wedge pressures maintained their tendency to increase in a linear manner with oxygen consumption (Vo
2
) on exercise after surgery. As a result of decreased wedge pressure, the pulmonary vascular resistance also decreased significantly afterward. The adequacy of cardiac output at rest and on exercise expressed by cardiac output as the linear function of Vo
2
improved toward the normal (values before operation, CO = 2.78 ± 0.0069 Vo
2
, r = 0.84; after operation, CO = 3.80 + 0.0062 Vo
2
, r = 0.91). The exercise factor (ΔCO/ΔVo
2
) or the regression coefficient, however, was similar before and after surgery. The hemodynamic result was satisfactory although some abnormalities of the left ventricular function persisted after operation.
Atresia of the Left Atrioventricular Orifice Associated with a Holmes Heart
Authors: QUERO MANUEL
Published: June 2012

The first well-documented case of Holmes heart associated with an atretic left atrioventricular orifice is reported. The Holmes heart may be considered as a single ventricle in which the main chamber has the morphologic characteristics of a left ventricle, the infundibular chamber is not inverted, and the great arteries are normally arranged. The importance of this report is greater than its simple description since it definitely establishes that coexistence of a true single ventricle and atresia of the atrioventricular orifice is possible.
Medico-Chirurgical Transactions
Authors: KIRSNER ALLAN B. , SHEON ROBERT P.
Published: June 2012

A cluster of papers, important to the history of cardiology and cardiovascular surgery, that were published in volume 1 of
Medico-Chirurgical Transactions
(1809), are discussed. These include articles by Sir Astley Cooper on ligature of the common carotid artery for aneurysm, John Abernethy on mitral stenosis, and Sir David Dundas on acute rheumatic carditis.
Hemodynamics of Aortic Valve Atresia
Authors: KROVETZ L. JEROME , ROWE RICHARD D. , SCHEIBLER GEROLD L.
Published: June 2012

Hemodynamic data on 12 infants with aortic valve atresia, ranging from 1 to 3 mo of age, are presented. Peripheral arterial oxygen saturations ranged from 19 to 93%. The lowest saturations were found in patients with closed foramen ovales. Increasing age, increasing pulmonary vascular resistance, and a decrease in the pulmonary-to-systemic blood flow ratio all correlated with decreasing systemic arterial oxygen saturation. In seven of the nine infants under 1 mo of age, systemic arterial saturations ranged from 81 to 93%. Thus, we feel that the classification of this lesion as a form of cyanotic congenital heart disease is misleading and prefer to classify aortic valve atresia as an obligatory admixture lesion. Criteria for selection of patients for surgery are discussed and the minimum amount of hemodynamic data needed for such selection is outlined.
Altered Platelet Function in Patients with Prosthetic Mitral Valves Effects of Sulfinpyrazone Therapy
Authors: WEILY HUGH S. , GENTON EDWARD
Published: June 2012

Platelet survival time and platelet adhesiveness and aggregation were examined in 16 patients with prosthetic mitral valves. Subsequently, nine patients were treated with sulfinpyrazone in doses of 400 mg and 800 mg/day, and the studies were repeated after a treatment period of 5 to 8 weeks.
51
Chromium survival time was shortened in 15 of 16 patients, and the mean value for the entire group was 5.49 ± 0.23 days (normal, 6.73 ± 0.21 days;
P
< 0.001). Mean platelet adhesiveness in glass bead columns was 53 ± 5% (normal, 30 to 60%). Platelet aggregation (turbidometric technic of Born) was normal. Treatment with 400 mg of sulfinpyrazone daily reduced platelet adhesiveness to 40 ± 5% (
P
< 0.05), but effected no change in platelet survival time or platelet aggregation. Therapy with 800 mg of sulfinpyrazone daily corrected platelet survival time to normal, 6.68 ± 0.57 days (
P
< 0.01), but it produced no further decrease in adhesiveness and no change in aggregation. It is concluded that platelet abnormalities regularly occur in patients with prosthetic mitral valves and may contribute to thromboembolism in this group. Platelet survival time is a more sensitive measure of altered platelet kinetics than platelet adhesiveness or platelet aggregation. Therapy with 800 mg of sulfinpyrazone per day corrects demonstrated abnormalities and may be useful for prevention of thromboembolism in patients with prosthetic mitral valves.
Relationship of Plasma Digitoxin and Digoxin to Cardiac Response Following Intravenous Digitalization in Man
Authors: SHAPIRO WILLIAM , NARAHARA KENNETH , TAUBERT KATHRYN
Published: June 2012

The value of plasma digitalis determinations will depend upon the accuracy with which they mirror the myocardial effects of digitalis. Ten volunteers received 0.8 mg of digitoxin intravenously, and after 2 hours the mean plasma digitoxin level was 45.6 ± 6 mµg/ml but declined over 4 to 6 hours during plasma-tissue equilibration. The cardiac response, as indicated by decreases in the left ventricular ejection time index (LVETI) and Q-S
2
intervals (
P
< 0.01), was present at 2 hours and reached maximum at 4 to 6 hours. Subsequently, plasma level, LVETI, and Q-S
2
changed in the same direction during slow excretion.

Six subjects received 1.0 mg of digoxin intravenously. Mean plasma digoxin at 30 min was 6.8 ± 0.3 mµg/ml; it fell after 3 to 4 hours to levels usually seen during maintenance digoxin administration (<3 mµg/ml) and then declined more slowly. Correlation of individual digoxin levels with ΔLVETI values during the first 4 hours was significant (
P
< 0.01). The half-life (T
½
) for the dominant slope of the plasma curve was 30.5 hours by plasma determinations and 29 hours by LVETI determination.

Plasma levels of digitoxin and digoxin were related to their cardiac effects under the conditions studied. Prior to plasma-tissue equilibration, plasma determinations of digoxin and digitoxin will be higher than levels seen during maintenance administration of these drugs.
Right Bundle-Branch Block Associated with Left Superior or Inferior Intraventricular Block
Authors: SCANLON PATRICK J. , PRYOR RAY , BLOUNT S. GILBERT
Published: June 2012

Over an 11-year period, 28 instances of acute myocardial infarction and bilateral bundle-branch block were encountered. Twenty-two of these patients had right bundle-branch block and left axis deviation, and six had right bundle-branch block and block of the inferior radiation of the left bundle. The overall incidence of complete heart block in these 28 cases was 21%. In-hospital mortality for the whole group was 36%, whereas it was 33% for those patients who developed complete heart block. From these results it is concluded that for the patient with bilateral bundle-branch block and acute myocardial infarction the prophylactic insertion of a temporary transvenous pacemaker is not only warranted, but is probably indicated.
Effects of Acute Digitalization on the Pulmonary Blood Volume in Patients with Heart Disease
Authors: MURPHY GERALD W. , SCHREINER BERNARD F. , YU PAUL N.
Published: June 2012

Basic hemodynamic data and the pulmonary blood volume (PBV) were determined in 23 patients before and after intravenous administration of acetyl strophanthidin during right and left heart catheterization. These patients were divided into two groups depending upon whether or not digitalization produced a significant fall in left ventricular end-diastolic pressure (LV
D
). Group I consisted of 11 patients who manifested a significant decrease in LV
D
, while in group II no change was noted after digitalization. In both groups, a significant rise in LV stroke volume, stroke work, and maximal rate of rise of LV systolic pressure (dp/dt) was recorded. In group I, a significant decrease in the pulmonary vascular distending pressure (P
d
) was accompanied by a decrease in PBV. In contrast, no change in P
d
or PBV was noted in the patients in group II. Changes in pulmonary vascular resistance (PVR) were inconsistent. It is concluded that: (1) in patients of group I the concordant decrease in P
d
and PBV represented a passive effect on the pulmonary vascular bed mediated by improved LV performance and decrease in LV
D
; (2) in patients of group II, despite evidence of significant positive inotropic effects on the left ventricle, the failure of LV
D
to fall prevented a decrease in P
d
and PBV; (3) no evidence of active vasomotor effects of acetyl strophanthidin in the lung could be demonstrated. Changes in PVR were capricious and not apparently useful in assessment of the presence or absence of pulmonary vasomotor effects induced by digitalis. The results of this study differ from the findings of other investigators in cardiac patients and experimental animals. Some of the differences may be attributed to different experimental methods and to species variation in vascular reactivity.

Also, the findings in this report contrast with those previously reported for isoproterenol and aminophylline, agents that produce both positive inotropic effects on the heart and active vasomotion in the pulmonary circulation.
Effects of Nitroglycerin on "Maximal" Oxygen Intake and Exercise Electrocardiogram in Coronary Heart Disease
Authors: DETRY JEAN-MARIE R. , BRUCE ROBERT A.
Published: June 2012

Oxygen intake (V

O
O2

) was measured during the last few minutes of a multistage treadmill test of maximal exercise in 12 healthy middle-aged persons, 32 patients with angina, and 23 survivors of myocardial infarction free of angina. Repetition of the same test, after each individual rested 30 min and took 0.4 mg nitroglycerin sublingually, increased V

O
O2

max in patients with angina (by 14.5%,
P
< 0.001) and in patients with prior infarction (by 6%,
P
< 0.005) but not in healthy persons. Angina at V

O
O2

max was prevented in 12 patients. Maximal heart rate was increased by 11% in the angina group and by 4% in the myocardial infarction group; the maximal blood pressure-heart rate product was increased (
P
< 0.005) only in patients with angina. [See Equation in PDF file] voltages from 50 to 69 msec after the nadir of S wave (S-T

b

) were quantified by computer averaging of 100 beat samples at several intervals during and after exercise. The amount of [See Equation in PDF file] depression during and after exercise was significantly reduced after administration of nitroglycerin in all three groups.

We conclude that nitroglycerin: (1) increases maximal circulatory conductance of O
2
in patients with coronary heart disease, whether or not limited by angina, mainly by increased maximal heart rate, and (2) lessens evidence of electrocardiographic myocardial ischemia and lowers frequency if angina pectoris despite the same or a higher pressure-rate index. These effects suggest a reduction in peripheral vascular tone and left ventricular end-diastolic pressure and volume with nitroglycerin.
Radiologic Notes in Cardiology
Authors: BARON MURRAY G.
Published: June 2012

The presence of a contrast interface indicates a difference in density between shadows of adjacent structures while the absence of an interface means that their radiodensities are similar. This is of considerable help in evaluating the presence or absence of opacified blood in any portion of the heart or great vessels on an angiocardiogram.
Syndrome of Hypoplasia of the Right Lung and Dextroposition of the Heart: "Scimitar Sign" with Normal Pulmonary Venous Drainage
Authors: MORGAN JACOB R. , FORKER ALAN D.
Published: June 2012

Reported is a case in which the clinical findings of the scimitar syndrome were present but with termination of the anomalous pulmonary vein into the left atrium. There was hypoplasia of the right lung, dextroposition of the heart, and the scimitar sign in the right lower lung field. Cardiac catheterization revealed no shunt, and on pulmonary angiograms, a large common right pulmonary vein curved toward the diaphragm (as in the usual case of the scimitar syndrome), but then reversed course to enter the left atrium. No connection with the inferior vena cava was present.
Interrelationships of Hepatic Blood Flow, Cardiac Output, and Blood Levels of Lidocaine in Man
Authors: STENSON ROBERT E. , CONSTANTINO ROBERT T. , HARRISON DONALD C.
Published: June 2012

Factors that regulate the arterial level of lidocaine during a constant infusion were investigated in 17 patients undergoing cardiac catheterization. Lidocaine was administered by a 50 mg bolus, followed by a constant infusion of 40 µg/kg/min until steady state conditions were achieved. Cardiac output and estimated hepatic blood flow were also determined. An inverse relationship between arterial lidocaine levels and cardiac index was observed. With a low cardiac index of 1.9 ± 0.3 liters/min/m
2
the arterial level was 2.4 (±0.4
sem
) µg/ml, while with a normal cardiac index of 3.3 ± 0.8 liters/min/m
2
it was 1.5 (±0.2
sem
) µ/ml.

A linear relationship was also observed between estimated hepatic blood flow and cardiac index. Therefore, an inverse relationship between arterial lidocaine levels and estimated hepatic blood flow was noted. At steady-state conditions, the liver accounted for 70% (±16%
sem
) of the metabolism or removal of the lidocaine administered. These studies suggest that the administration of smaller doses of lidocaine will produce effective therapeutic levels when reduced hepatic blood flow exists.
Pathophysiology of the Pulmonary Circulation in Emphysema Associated with Alpha
1
Antitrypsin Deficiency
Authors: STEIN PAUL D. , LEU JERRY D. , WELCH MARTIN H. , GUENTER CLARENCE A.
Published: June 2012

Patients with homozygous alpha
1
antitrypsin deficiency present a unique opportunity for evaluation of the pulmonary vasculature in primary emphysema. In five patients, the detailed angiographic appearance of small (0.2-2.0 mm diameter) muscular pulmonary arteries, shown by wedge arteriography, was correlated with the results of right heart catheterization during the control hypoxemic state (average arterial P

o
o2

50 mm Hg), the administration of oxygen (average arterial P

o
o2

90 mm Hg), and a constant infusion of aminophylline. In all patients, wedge arteriograms in the lower zones of the lungs showed a sparsity of arborization and a diminished background blush of capillary filling. These abnormalities were in the areas of diminished pulmonary blood flow, as indicated by the pulmonary scintiscans and the capillary phase of pulmonary arteriograms. The administration of oxygen and of aminophylline produced an increase in the diameter of arteries 0.5 to 2 mm in diameter on the wedge arteriograms of some of the patients. The average pulmonary arterial mean pressure, 30 mm Hg, and average pulmonary vascular resistance, 300 dyne-sec-cm
–5
, were both elevated during the control hypoxemic state and decreased in each patient during the administration of oxygen and of aminophylline. This study demonstrates abnormalities of the small pulmonary arteries in patients with alpha
1
antitrypsin deficiency. These abnormalities may be responsible for pulmonary hypertension and altered regional perfusion.
Left Bundle Branch Block
Authors: HAFT JACOB I. , HERMAN MICHAEL V. , GORLIN RICHARD
Published: June 2012

Coronary angiography, cine left ventriculography, and the cardiovascular hemodynamics of 24 patients with left bundle branch block were studied. Seven patients were found to have significant coronary artery disease, always severe. Five had cardiomyopathy and seven had valvular disease. Only those with coronary artery disease or cardiomyopathy had abnormal left ventricular contraction patterns. The onset of left ventricular contraction was delayed in the patients with left bundle branch block, but the period of isovolumic contraction was normal in those without severe underlying disease. Left axis deviation in addition to left bundle branch block did not imply more frequent coronary atherosclerosis.
Slopes of the Carotid Pulse Wave in Normal Subjects, Aortic Valvular Diseases, and Hypertrophic Subaortic Stenosis
Authors: LYLE DOUGLAS P. , BANCROFT WILLIAM H. , TUCKER MARJORIE , EDDLEMAN E. E.
Published: June 2012

Variations in certain slopes of the carotid pulse which exist among normal subjects, patients with aortic valvular disease, and those with hypertrophic subaortic stenosis were examined. Records from 256 subjects were quantified with computer technics. The externally recorded volume pulses were related to simultaneously recorded brachial artery pressures (cuff); thus the slopes are expressed in mm Hg/sec. Several slopes were studied: the maximum rate of pressure rise, the mean systolic upstroke (onset of carotid upstroke to peak systolic excursion), and the least square fits of the first twothirds of the upstroke and the first two-thirds of diastole. The least square slopes of 98% of the patients with aortic stenosis were <457 mm Hg/sec, whereas none of those with hypertrophic subaortic stenosis was that low. The greatest overlap was between patients with aortic stenosis and those with aortic stenosis and aortic insufficiency. The slopes correlated poorly with valve areas and gradient in aortic stenosis and combined aortic stenosis and aortic insufficiency. The least square slope in normal subjects is not related to heart rate or age. Thus, the decreased slopes in patients with aortic stenosis are related to many factors, including myocardial function, but influenced by the size of the aortic valve opening and the properties of the vessels.
Ventricular Fibrillation
Authors: DREIFUS LEONARD S. , HAIAT ROBERT , WATANABE YOSHIO , ARRIAGA JAIME , REITMAN NORMAN
Published: June 2012

A case of Wolff-Parkinson-White syndrome associated with ventricular fibrillation is presented. The control of recurrent ventricular fibrillation with large doses of digitalis and other antiarrhythmic drugs, including propranolol, lidocaine, procainamide, and quinidine, is discussed. As far as we can determine, this is the first human case in which the precise onset of ventricular fibrillation was documented. Possible mechanisms are presented that may produce ventricular fibrillation in patients with Wolff-Parkinson-White syndrome associated with atrial flutter or fibrillation.
Isolated Tricuspid Insufficiency
Authors: MORGAN JACOB R. , FORKER ALAN D.
Published: June 2012

Isolated tricuspid insufficiency can be a well-tolerated lesion, as illustrated by a 32-year follow-up in one patient reported here. A second case of recent onset is also described. The 13 reported cases of isolated tricuspid insufficiency due to trauma can be divided into two groups: ruptured papillary muscle or ruptured chordae tendineae and/or valve. All patients with ruptured papillary muscle were dead or had surgery within 4 months after trauma. The earliest surgery in the chordae tendineae group was 1½ years after trauma. Physical findings in isolated tricuspid insufficiency are distinctive; the electrocardiogram usually shows incomplete right bundle-branch block, and the chest roentgenogram shows cardiomegaly. Indicator-dilution curves from the right atrium and pulmonary artery are useful for confirmation of the diagnosis. Surgery is indicated when papillary muscles are ruptured, but conservative treatment is probably usually indicated in the other patients.
Double-Outlet Right Ventricle Without Pulmonic Stenosis
Authors: GOMES MANUEL M. R. , WEIDMAN WILLIAM H. , MCGOON DWIGHT C. , DANIELSON GORDON K.
Published: June 2012

The results of complete repair of double-outlet right ventricle without pulmonic stenosis in 18 Mayo Clinic patients are analyzed; the over-all operative mortality rate was 22%. Pulmonary vascular obstructive disease and a second ventricular septal defect of the atrioventricular canal type were associated with a higher mortality rate. The difficulties in the diagnosis of this uncommon condition are emphasized.

Patients with double-outlet right ventricle without pulmonic stenosis should have complete repair early in life before the onset of severe pulmonary vascular obstructive disease-the only specific contraindication to operation. Pulmonary artery banding may be preferable as a first-stage palliative procedure in infants less than six months old who do not respond to medical therapy.
Lipids in Silicone Rubber Valve Prostheses After Human Implantation
Authors: CHIN H. P. , HARRISON EARL C. , BLANKENHORN DAVID H. , MOACANIN JOVAN
Published: June 2012

Fourteen prosthetic valves were obtained from human recipients at autopsy or valve replacement surgery. The silicone rubber poppets were extracted with lipid solvent and examined by thin-layer chromatography, infrared absorption spectroscopy, and phosphorus analysis. The significant findings were: (1) No phospholipid was present in any of the valves; neither was there any protein. (2) The relative content of cholesterol, cholesteryl ester, fatty acid, and triglyceride varied widely. (3) Residual uncured silicone polymers were found in all valves; in one patient these appeared to combine with lipid and form a component with unusual chromatographic behavior.
Physiological Evaluation of Chronic Right Ventricular Bypass
Authors: LAFARGE C. GRANT , BANKOLE MICHAEL , BERNHARD WILLIAM F.
Published: June 2012

Investigations with an implantable left ventricular (LV) assist pump indicated inadequate circulatory support in the presence of induced ventricular fibrillation (VF). Consequently, a right ventricular (RV) bypass pump was developed to provide a stable pulmonary blood flow. This report evaluates the physiological effects of the RV pump alone and in conjunction with an LV pump.

Eleven calves have been evaluated by standard cardiac catheterization techniques during chronic pumping (1 to 85 days, mean 30 days, and continuing). Pressures, flows, and RV and LV function were monitored with transducer-tipped catheters and angiography. Effective pulmonary compliance was also measured. The RV bypass studies revealed (1) pump capability up to 8 L/min, reducing RV pressure and work to zero, (2) pulmonary artery pressure not significantly increased (20 to 40 mm Hg), (3) pulmonary compliance identical with sham-operated calves, and (4) no pathological changes noted in lungs. Data suggest that biventricular bypass pumps will provide chronic circulatory support during VF or biventricular failure.
Fate of Orally Administered
3
H-Digitoxin in Man with Special Reference to the Absorption
Authors: BEERMANN BJÖRN , HELLSTRÖM KJELL , ROSÉN ANDERS
Published: June 2012

3
H-digitoxin and polyethylene glycol (nonabsorbable marker) were given orally to five subjects provided with a gastrointestinal tube. Of the radioactivity administered, approximately 15, 30, and 70% had been absorbed when the test solution was passing the stomach, the duodenum, and the upper jejunum, respectively. The absorption was rapid, and the plasma contained detectable amounts of radioactivity after 5 minutes. There was no evidence of a disposition of
3
H-digitoxin in intestinal aspirates. On a sixth subject labeled digitoxin was instilled in the mid-jejunum. The concentration of label in the plasma and the pattern of elimination of radioactivity in the urine and the feces in this subject indicated that the absorption of digitoxin was effective also in the more distal part of the gut. The combined results from the present study indicate that the absorption of orally administered digitoxin is complete.

The biliary excretion of label 4 to 24 hours after the start of the experiments was calculated from the bilirubin turnover and the mean radioactivity per mg bilirubin in duodenal aspirates obtained after intravenous injections of cholecystokinin. Less than 10% of the administered dose appeared to be excreted with the bile.

The radioactivity recovered in plasma showed less decomposition than that found in duodenal bile and urine.
Maximal Treadmill Stress Test Correlated with Postexercise Phonocardiogram in Normal Subjects
Authors: ARONOW WILBERT S. , PAPAGEORGE'S NICHOLAS P. , UYEYAMA RONALD R. , CASSIDY JOHN
Published: June 2012

One hundred normal subjects, mean age 51, who had had a simultaneous phonocardiogram and electrocardiogram at rest and after a double Master's test had a maximal treadmill stress test. Thirteen of 100 normal people (13%) had an abnormal maximal treadmill stress test with at least 1.0 mm of ischemic ST-segment depression. Ten of 29 normal subjects (34%) with a fourth heart sound and four of 11 normal people (36%) with a third heart sound after their double Master's test had an abnormal maximal treadmill stress test. Three of 71 normal subjects (4%) without a fourth heart sound and nine of 89 normal people (10%) without a third heart sound after their double Master's test had an abnormal maximal treadmill stress test. Normal subjects with an abnormal maximal treadmill stress test had a significantly higher incidence of fourth heart sounds (
P
<0.001) and third heart sounds (
P
<0.02) than normals with a normal maximal treadmill stress test.
Double-Outlet Right Ventricle with Pulmonic Stenosis
Authors: GOMES MANUEL M. R. , WEIDMAN WILLIAM H. , MCGOON DWIGHT C. , DANIELSON GORDON K.
Published: June 2012

The results of complete repair of double-outlet right ventricle with pulmonic stenosis in 22 Mayo Clinic patients were analyzed. The overall mortality rate was 32%. Since 1960, the mortality rate has been reduced to 16%. Anomalies of the distribution of the right coronary artery, a second ventricular septal defect of the atrioventricular canal type, and significant residual pulmonic stenosis were associated with a higher mortality rate. The difficulties in the diagnosis of this uncommon condition are emphasized.

Complete repair is best carried out after the patient is 4 years old. A systemic-to-pulmonary arterial shunt is the procedure of choice for those who are younger than this. In the occasional patient with anomalous distribution of the right coronary artery which precludes adequate relief of the pulmonic stenosis, use of an aortic homograft from the right ventricle to the pulmonary artery should be considered.
Evaluation of Sino-atrial Node Function in Man by Overdrive Suppression
Authors: MANDEL WILLIAM , HAYAKAWA H. , DANZIG RONALD , MARCUS HAROLD S.
Published: June 2012

Sino-atrial node (SAN) function was evaluated in 46 patients, three of whom had the sick sinus syndrome. Patients were paced from the right atrium for 15 to 180 sec at rates of 90, 110, 130, and 150 beats/min. The rapid cessation of pacing was associated with suppression of the SAN at all paced rates and at all durations of pacing. The observed pause was terminated by a sinus beat in all instances. The duration of pacing had little influence on the duration of the observed pause. The pause increased as the pacing rate was increased until, at a rate of 150 beats/min, a marked decrease in the pause was noted. Atropine (1.5-3.0 mg iv) diminished but did not eliminate the SAN suppression. Subthreshold pacing did not suppress SAN function. Three patients with sick sinus syndrome had a greater degree of SAN suppression than normal patients (4732 ± 415 msec [SSS] M ±
sem
; 1041 ± 56 msec for normal patients).

The determination of the duration of the pause following cessation of atrial pacing provides a technique for recognition of abnormalities of SAN function.
Fine Structure of the His Bundle
Authors: JAMES THOMAS N. , SHERF LIBI
Published: June 2012

The fine structure of the His bundle is described on the basis of its light and electron microscopic appearance. Electron microscopy was performed on one human and two canine hearts, and light microscopy on over 400 human and 60 canine hearts. The His bundle was identified by its light microscopic appearance. There were no significant differences in the fine structure of human and canine His bundles. In both, the principal cell was a typical Purkinje cell containing few myofibrils and a large perinuclear clear zone; these cells are shorter and broader than working myocardial cells, and their intercellular junctions (which are obliquely rather than transversely oriented) contain a high proportion of nexus formations. Both the human and canine His bundles are partitioned by fine collagen septa, which are longitudinally oriented with comparatively few crossover connections. The general organization of the His bundle is thus into multiple strands of Purkinje cells, and these strands are largely separated from one another by collagen. This longitudinal separation of Purkinje strands by collagen, plus the specialized nature of intercellular junctions within each strand, form an anatomic basis for suspecting longitudinal separation of conduction within the normal His bundle. Some electrophysiologic implications of these findings are discussed.
Alterations in the Circulatory Response to Exercise Following a Meal and Their Relationship to Postprandial Angina Pectoris
Authors: GOLDSTEIN ROBERT E. , REDWOOD DAVID R. , ROSING DOUGLAS R. , BEISER G. DAVID , EPSTEIN STEPHEN E.
Published: June 2012

In order to study the mechanisms responsible for the more rapid precipitation of angina in the postprandial state, we evaluated the circulatory response to upright bicycle exercise in 12 patients with angina before and after a meal. Eleven of 12 subjects developed angina sooner after eating (average 1.3 min,
P
< 0.001). Comparison of circulatory responses revealed that a given amount of postprandial exercise resulted in faster heart rate (12 beats/min,
P
< 0.001) and greater blood pressure (6 mm Hg,
P
< 0.05). The product of blood pressure and heart rate (an index of myocardial oxygen demand) at onset of angina during postprandial exercise was the same as corresponding preprandial values. Our results suggest that the accelerated development of angina during exercise after meals is primarily due to a more rapid rise in heart rate and blood pressure, factors tending to augment myocardial oxygen requirements, rather than the result of a deleterious effect of digestion and absorption on myocardial oxygen delivery.
Cold Hypersensitivity in Raynaud's Phenomenon
Authors: JAMIESON GLYN GARFIELD , LUDBROOK JOHN , WILSON ALAN
Published: June 2012

We have sought evidence that local cooling enhances the adrenergic neurotransmitter mechanism in resistance vessels in the hands of subjects with Raynaud's phenomenon. The method used was to examine the magnitude and time-course of the reflex vasoconstriction in the hand which follows application of ice to the neck. One hand of each subject was kept at 26°C and the other at 36°C, while the general thermal environment was varied. Enhancement was found in three groups of subjects: those with idiopathic, early age-onset, Raynaud's disease; those with Raynaud's phenomenon of late age-onset; and those with systemic scleroderma. It was absent in normal subjects. The effect could not be accounted for by structural abnormalities of resistance vessels, blood abnormalities, nor by interference with norepinephrine reuptake or dissipation at the neuro-effector junction.
Mean Velocity of Fiber Shortening
Authors: KARLINER JOEL S. , GAULT JAMES H. , ECKBERG DWAIN , MULLINS CHARLES B. , ROSS JOHN
Published: June 2012

Previously it was shown that left ventricular (LV) myocardial contractility can be assessed from the instantaneous relation between velocity of fiber shortening and maximum LV wall tension (V
CF
at max T). Such analysis is complex, requiring frame-by-frame correlation of LV dimensions with pressure, and a simpler approach was sought. In 50 patients the mean velocity of circumferential fiber shortening (mean V
CF
), determined from the systolic excursion of the LV internal minor equator obtained by cineangiography, was compared with instantaneous tension-velocity relations. In 13 subjects without LV disease, V
CF
at max T averaged 1.74 ± 0.31 (mean ±
sd
) circumferences (circ)/sec (range, 1.37-2.52); corresponding mean V
CF
was 1.50 ± 0.27 circ/sec (range, 1.23-2.03). In 22 patients with LV myocardial disease V
CF
at max T averaged 0.64 ± 0.29 circ/sec (range, 0.12-1.27); mean V
CF
averaged 0.68 ± 0.36 circ/sec (range, 0.15-1.29,
P
< 0.001 compared with normal subjects). Similar results were obtained in 15 patients with valvular lesions and an abnormal V
CF
at max T. Mean V
CF
detected impaired myocardial function in 95% of patients with abnormal instantaneous tension-velocity relations, and in the remaining 5% the amount of overlap between normal and abnormal mean V
CF
was slight. The extent of fiber shortening and the percent shortening of the internal diameter at the minor equator did not provide separation of normal from abnormal groups. It is concluded that the mean velocity of fiber shortening provides a simplified method of estimating LV contractility which: (1) requires analysis of only two frames of a cineangiogram; (2) allows quantitative comparison of LV myocardial contractility among patients; (3) adequately detects altered cardiac performance, even when valvular disease and myocardial dysfunction coexist.