bluuebunny/crossref_metadata_2025 huggingface dataset:
Acute Hemodynamic Effects of Dopamine in Patients with Shock
Authors: LOEB HENRY S. , WINSLOW EDWARD B. J. , RAHIMTOOLA SHAHBUDIN H. , ROSEN KENNETH M. , GUNNAR ROLF M.
Published: June 2012

The hemodynamic effects of dopamine were studied in 62 patients with clinical shock. In 36 patients with infection dopamine increased mean arterial pressure (MAP) 30%, and cardiac output (CO) 37%. Urine flow (UF) increased from 0.5 ml/min to 1.6 ml/min. Norepinephrine (NE) in 26 patients resulted in a higher MAP, lower CO, and similar UF. Isoproterenol (Isp) in 19 patients resulted in a lower MAP, higher CO, and a significantly lower UF. In 13 patients with cardiogenic shock dopamine increased MAP 6%, and CO 40%. UF increased from 0.6 ml/min to 1.1 ml/min. NE in eight patients resulted in a lower CO than during dopamine infusion, and Isp in five patients resulted in a higher CO. Dopamine improves MAP pressure, CO, and UF when shock is due to infection and is superior to Isp which does not increase perfusion pressure to adequate levels and does not improve UF. In patients with cardiogenic shock who have reduced CO and increased systemic vascular resistance, perfusion pressure tended to be adequate, and improved CO occurred with dopamine and Isp but not with NE. Although Isp increased CO more than dopamine, differences in regional perfusion are important in selection of the best inotropic agent and in most patients make dopamine the preferred agent.
Reliability of Individual Frontal Plane Axis Determination
Authors: OKAMOTO NOBORU , KANEKO KATSUMI , SIMONSON ERNST , SCHMITT O. H.
Published: June 2012

In a sample of 649 healthy men, the QRS and T amplitude frontal plane QRS and T axes and mean vectors were determined from leads I and III (standard reference), II and III, I and II, I and aV
F
, aV
L
and aV
F
, and from a vectorial combination of leads I, II, and III. The group means were similar, but there were large intraindividual differences of the QRS axis (up to ± 35°) and, to a somewhat lesser degree, of the T axis between the different lead combinations. Hypothetically, the axes from different lead combinations should be identical. The intraindividual discrepancies of the mean frontal plane vectors were also large (about 20%). In a smaller sample of 50 healthy men the axis was also determined from Frank X, Y leads, and the QRS and T axes were determined from both amplitudes (as in the larger sample) and areas. The results were similar to those obtained in the larger sample: no significant differences in the group means, but large intraindividual discrepancies between the various lead combinations both for amplitude and area axes. It is concluded that the normal standards obtained for the axis determined from leads I and III are also valid for the other lead combinations, but that for the individual patient there is no assurance that the axis determined from any one lead combination will be the true axis, even with a liberal range of error. The major part of the variation in axis as measured from various lead combinations is attributable in this study to time disparity between components measured in the individual leads, but skin impedance contributes substantially in many conventional measurements. For a patient in whom the axis is considered to be of diagnostic importance, it is probably worth averaging axes determined by several different lead combinations.
Transient and Persistent Atrial Standstill with His Bundle Lesions
Authors: ROSEN KENNETH M. , RAHIMTOOLA SHAHBUDIN H. , GUNNAR ROLF M. , LEV MAURICE
Published: June 2012

Electrophysiologic studies, including His bundle recording and atrial pacing (AP), were performed in one patient with transient (TAS) and another with persistent atrial standstill (PAS). Both subsequently expired, and postmortem examinations with serial sections of the conduction system were obtained. The patient with TAS had left bundle-branch (LBB) block, a P-H interval of 140 msec (normal, 80-140 msec), an H-Q of 40 msec (normal, 35-55 msec), and an AP threshold of 1.2 ma. Postmortem examination revealed total left circumflex occlusion proximal to the sinoatrial (SA) nodal artery takeoff, SA nodal arteriolosclerosis without infarction, and left-sided cardiac skeletal sclerosis (LSCSS) disrupting the penetrating portion of the His bundle and the LBB. Intracardiac recordings in the patient with PAS showed absent atrial activity and an H-Q of 60 msec. The atria were inexcitable with AP up to 15 ma at multiple sites. Postmortem examination revealed a previously undescribed atrial disease characterized by arteriolosclerosis, fibroelastosis, fatty infiltration, and vacuolar degeneration of muscle cells, with only moderate SA and A-V nodal involvement. LSCSS was present, disrupting the branching portion of the His bundle. Thus, TAS reflected SA nodal ischemia without infarction; PAS reflected a new atrial degenerative disease; H-Q was normal with a lesion in the penetrating portion of the His bundle and was prolonged with a similar lesion in the branching portion.
Myocardial and Body Metabolism in Fatal Cardiogenic Shock after Valvular Replacement
Authors: MOFFITT EMERSON A. , MOLNAR GEORGE D. , MCGOON DWIGHT C.
Published: June 2012

Cellular energy substrates and metabolites, electrolytes, oxygenation, and acid-base balance, in arterial and coronary sinus blood of seven adult patients who died after valvular replacements, were studied and compared with these measurements from five patients having aortic replacement who survived. Six of the patients were in New York Heart Association class IV. All but one died within 24 hr of acute circulatory failure, with excessive bleeding being a contributing factor. Plasma potassium and osmolality remained higher in the first postoperative hours in nonsurvivors. Ketone bodies, growth hormone, and lactate levels rose precipitously as shock became severe. Increased arterial blood osmolality and potassium, plus a still-rising lactate concentration, were evident 2 hr after operation in patients who died in the next 24 hr. Low cardiac output, hyperosmolality, and the degree of lactic acidosis were the only early changes predicting the fatal outcome.
Relationship of Cardiorenal Function to Renin-Aldosterone System in Patients with Valvular Heart Disease
Authors: JUDSON WALTER E. , HELMER OSCAR M.
Published: June 2012

Metabolic data obtained during sodium (Na) loading, restriction, and depletion with thiazide were compared in 23 patients with valvular heart disease who had cardiac indices (CI) > and < 2.5 liters/min/m
2
. During Na loading (80 mEq Na for 4 days, followed by 150 mEq for 4 days) patients with CI > 2.5 excreted –3.4% Na load than those with the lowest normal values, whereas those with CI < 2.5 excreted –20.8% (
P
< 0.02). All 12 patients with CI > 2.5 responded to Na loss with elevation of plasma renin activity (PRA). In contrast, of the ill patients with CI < 2.5, none of the six on the 10 mEq diet, and only two of five on thiazide, responded with an increase in PRA; the urinary aldosterone values paralleled the PRA responses. The renin-angiotensin-aldosterone system responded to changes in Na balance. The magnitude and direction of the responses were influenced by cardiohemodynamic abnormalities. Aldosterone plays an important role in the Na retention in patients with valvular heart disease by stimulating Na-K exchange in the distal tubules of the kidney.
Production of Increased Right-to-Left Shunting by Rapid Heart Rates in Patients with Tetralogy of Fallot
Authors: KING SPENCER B. , FRANCH ROBERT H.
Published: June 2012

A patient with tetralogy of Fallot who developed cyanosis and tachypnea during spontaneous attacks of paroxysmal atrial tachycardia had an increase in right-to-left shunting with a fall in arterial oxygen saturation from 96 to 43%. Duplication of the fast heart rate by atropine and atrial pacing reproduced these hemodynamic changes, while slowing the rate with propranolol reversed this effect. Subsequently, six patients with mild tetralogy of Fallot underwent rapid atrial pacing during cardiac catheterization. This primary increase in heart rate resulted in a fall in systemic oxygen saturation, an increase in percent right-to-left shunt, and an increase in the right ventricular outflow pressure gradient. These data suggest that further narrowing of the right ventricular infundibulum may occur during tachycardia. This experience indicates that paroxysmal atrial tachycardia should be added to the conditions that can cause increased cyanosis in some patients with tetralogy of Fallot. Other tachycardias may also augment right-to-left shunting.
Pericardial Effusion
Authors: BARON MURRAY G.
Published: June 2012

Both a pericardial effusion and a failing myocardium can produce the roentgen appearance of a large, smoothly dilated heart which shows little evidence of pulsations. The correct diagnosis is often suggested by the appearance of the hilar vessels which are usually obscured by the cardiac shadow that is enlarged by a pericardial effusion, and not by the failing heart with dilatation of its chambers. Displacement of the epicardial fat line within the cardiac silhouette can be pathognomonic for a pericardial effusion. A normal pericardial shadow outlined by epicardial and retrosternal fat lines, seen on the lateral chest film, will exclude a pericardial effusion from consideration. A conclusive diagnosis of a pericardial effusion can be made by angiocardiography.
Serial Observations on Left Ventricular Dysfunction in Acute Myocardial Infarction
Authors: HEIKKILÄ JUHANI , LUOMANMÄKI KIMMO , PYÖRÄLÄ KALEVI
Published: June 2012

Systolic time intervals corrected for heart rate were studied serially in 50 patients with acute myocardial infarction (AMI) 1, 5, and 20 days after the onset of symptoms from simultaneously recorded kineto-, phono-, and electrocardiograms and carotid artery pulse tracings. Left ventricular ejection time (LVET), electromechanical systole (QA
2
), and mechanical systole (M
1
A
2
) decreased from the first to the fifth day (
P
< 0.001) and increased again toward normal by the twentieth day. There was a clear correlation with the clinically assessed severity of AMI; the high prevalence of abnormal values indicated a frequent and early impairment of left ventricular performance. In severe power failure, deterioration was indicated by progressive shortening of the systolic time intervals, as contrasted to gradual improvement noted in uncomplicated infarctions. Similarly, LVET, QA
2
, and M
1
A
2
displayed a significant correlation with the grade of radiologically assessed pulmonary vascular congestion on the first day. A relationship between LVET, QA
2
, and isovolumic contraction time (ICT)/LVET and the degree of paradoxical cardiac pulsation became apparent on the fifth day. LVET, M
1
A
2
, ICT/LVET, and preejection period (PEP)/LVET were more abnormal in the nine patients who died than in the 41 survivors (
P
< 0.05). PEP and ICT showed no correlation with clinically or radiologically assessed severity or prognosis of infarction, in contrast to findings in chronic heart failure. Decrease of contractility in AMI appears not to be directly reflected in preejection intervals. These findings indicate the value of externally measured left ventricular systolic time intervals, especially LVET, in assessment of the severity and prognosis of AMI.
Natural History of Rheumatic Aortic Regurgitation
Authors: SPAGNUOLO MARIO , KLOTH HOWARD , TARANTA ANGELO , DOYLE EUGENIE , PASTERNACK BERNARD
Published: June 2012

The medical courses of 174 young patients with aortic regurgitation were followed prospectively for a median of 10 years. The data were analyzed by life-table methods; congestive failure and angina, as well as death, were considered as end points, since the occurrence of the former is considered sufficient indication for aortic valve replacement. Thirty-one patients developed the triad of moderate or marked left ventricular enlargement, two or three electrocardiographic abnormalities, and abnormal blood pressure. Thirty-three percent of these patients
either
died
or
had failure or angina within 1 year, 48% within 2 years, 65% within 3 years, and 87% within 6 years from the acquisition of the triad. The 71 patients with none of the above features had uneventful courses. Of the 71 patients with one or two features only seven
either
died (three)
or
became symptomatic. These data are useful for patient selection for surgery before symptoms appear.
Effects of Physical Training on Exertional S-T-Segment Depression in Coronary Heart Disease
Authors: DETRY JEAN-MARIE , BRUCE ROBERT A.
Published: June 2012

Symptom-limited maximal oxygen intake (V

O
O2 S-L

) and electrocardiographic responses to multistage treadmill test were determined before and after 3 months of physical training in 14 patients with coronary heart disease. Six patients also had hemodynamic studies done at several submaximal work loads in the upright position before and after training. S-T-segment responses were measured by computer averaging of 100-beat samples.

After physical training, the heart rate (
P
< 0.01) and the product of heart rate and systolic blood pressure (
P
< 0.02) at
submaximal
exercise were lower and attended by significantly less S-T-segment depression. At
maximal
exercise, however, the heart rate (
P
< 0.01) and the product of heart rate and systolic blood pressure (
P
< 0.02) were higher after training, and the S-T-segment depression was more pronounced (
P
< 0.005). The quantitative relationships of S-T-segment depression to either exercise heart rate, product of heart rate and systolic blood pressure, or to pressure-rate product (product of heart rate and mean blood pressure) were unaffected by physical training. The V

O
O2 S-L

increased by 20.8% (
P
< 0.001); the product of heart rate and systolic blood pressure at symptom-limited exercise increased by 10% (
P
< 0.005) in the angina patients, which may indicate a higher angina threshold after physical training.

It is concluded that physical training of coronary patients changes S-T-segment responses to submaximal and maximal exercise: these modifications presumably result from changes in heart-rate and blood-pressure responses to exercise, rather than from an improved coronary circulation.
Isolated Right Ventricular Hypoplasia
Authors: VAN DER HAUWAERT LUC G. , MICHAELSSON MAGNUS
Published: June 2012

Hypoplasia of the right ventricle, unassociated with severe pulmonary or tricuspid valvar malformations, is a primary congenital abnormality in which the trabeculated sinus portion of the ventricle fails to develop. An atrial septal defect or a stretched foramen ovale serves as an escape valve. The clinical, hemodynamic, and angiocardiographic features of this rare type of cyanotic heart disease are described in two children and reviewed in 13 previously reported cases. The clinical spectrum varies considerably in accordance with the degree of hypoplasia. Severe forms of hypoplasia, usually presenting in infancy, closely resemble tricuspid or pulmonary atresia. The electrocardiogram in hypoplasia, which shows right atrial enlargement and absence of right ventricular electrical forces, may be indistinguishable from an electrocardiogram in atresia. Lesser degrees of hypoplasia should be differentiated from Ebstein's malformation and anomalies of the systemic venous return. Both our patients, who had only mild underdevelopment of the right ventricle, markedly improved after surgical closure of the atrial septal defect. It is proposed that in mild forms of hypoplasia temporary occlusion of the atrial septal defect by means of a balloon catheter should be used in the preoperative assessment of right ventricular function.
Interlobar Effusion
Authors: BARON MURRAY G.
Published: June 2012

Congestive heart failure is the most common cause of an interlobar pleural effusion. The correct diagnosis is usually evident on the lateral chest film which shows the characteristic spindle-shaped shadow within the plane of the fissure and continuous with a line of thickened pleura at one or both ends. In the frontal view, however, the identity of such an effusion, especially when it involves the long fissure, is considerably less evident. The possibility of an interlobar effusion should be considered whenever a poorly defined shadow is seen in the central portion of the lung and is associated with evidence of pulmonary congestion and cardiomegaly.
Relationship Between Changes in Left Ventricular Dimensions and the Ejection Fraction in Man
Authors: LEWIS RICHARD P. , SANDLER HAROLD
Published: June 2012

Left ventricular length and calculated diameter were derived from angiocardiograms in 24 subjects with various heart diseases. Chamber diameter was noted to decrease an average of 27.5% from end-diastole to end-systole, and chamber length decreased 13%. Only subjects with calculations of left ventricular mass differing less than 25% from end-diastole to end-systole were accepted in order to avoid effects of spurious increases in end-systolic wall thickness on calculated diameter. Patients with localized disorders of contraction were also excluded. An extremely close linear relationship between the percentage change in diameter and the ejection fraction was demonstrated. Analysis of the radii of curvature showed that the lateral wall usually straightens during systole. However, if extreme ventricular dilatation is present, the lateral-wall curvature increases with systole. The possible implications of this alteration in contraction pattern and its effect upon the ejection fraction were discussed.
Diagnostic Import of QRS Notching in High-Frequency Electrocardiograms of Living Subjects with Heart Disease
Authors: FLOWERS NANCY C. , HORAN LEO G.
Published: June 2012

In a 10-month period 92 patients have been studied for the occurrence of high-frequency notching in orthogonal electrocardiographic leads X, Y, and Z obtained by high-frequency, high-speed techniques. The same patients were studied radiographically with barium, with routine electrocardiograms, hemodynamically at cardiac catheterization and, in many instances, with left ventricular angiograms. Sixty-nine patients had not had cardiac surgery prior to recording and had normal duration of ventricular activation. These patients were placed into groups which included those with no ventricular enlargement, isolated right ventricular enlargement, isolated left ventricular enlargement, and biventricular enlargement.

The patients with no ventricular enlargement had a mean of 2.9 notches and never exceeded a total notch count of 6. Those with single ventricular enlargement had a mean of between 5 and 6, while those with biventricular enlargement frequently exceeded 6 notches and had a mean of 8.6. The differences were statistically significant.

We concluded, then, that notch count correlates well with the dynamic evidence of ventricular enlargement in a living population. Since the effect is additive, biventricular enlargement elevates the counts sufficiently to remove the overlap with normal seen in groups with univentricular enlargement.
Immunoglobulin Binding in Cardiomyopathic Hearts
Authors: DAS SUNIL K. , CALLEN JEFFERY P. , DODSON VERNON N. , CASSIDY JAMES T.
Published: June 2012

Bound gamma globulin was demonstrated by the direct immunofluorescent technique in heart tissue from three patients with severe congestive cardiomyopathy. In two of these patients complement (β
1
C) was also bound to the heart muscle. Heart tissue from one of six patients who died of myocardial infarction showed a trace of bound gamma globulin, but no bound complement. During life, the heart in advanced cardiomyopathy may preferentially fix heart-reactive immunoglobulins to specific sarcolemmal and subsarcolemmal antigens, and antiheart antibody may not be detectable in the serum.
Effects of Chronic Heart Failure on the Capacity of Glucagon to Enhance Contractility and Adenyl Cyclase Activity of Human Papillary Muscles
Authors: GOLDSTEIN ROBERT E. , SKELTON C. LYNN , LEVEY GERALD S. , GLANCY D. LUKE , BEISER G. DAVID , EPSTEIN STEPHEN E.
Published: June 2012

Glucagon has a positive inotropic effect in normal hearts but is ineffective in animals with chronic cardiac failure. To assess directly the influence of glucagon on the human myocardium, we measured contractility and activation of adenyl cyclase, the enzyme thought to mediate the inotropic action of glucagon, in left ventricular papillary muscles obtained from 12 patients at mitral valve replacement. On the basis of preoperative ventricular end-diastolic pressures and cardiac output (independent of papillary muscle data) patients were classified in three groups: normal, cardiac failure, and condition indeterminate. Concentration-response curves showed that glucagon caused a mean rise of 11% in peak papillary muscle tension and a rise of 12% in peak rate of tension development in the normal patients; myocardial adenyl cyclase activity from each normal patient rose after glucagon (average, 84%). In the papillary muscles of the patients with cardiac failure, glucagon did not augment either tension or adenyl cyclase activity. In contrast, contractility and adenyl cyclase activity increased after norepinephrine in both normal patients and those with cardiac failure. The indeterminate group had two patients whose papillary muscles responded to glucagon and two whose papillary muscles did not respond. Thus, direct study of human papillary muscles shows that chronic cardiac failure is uniformly associated with complete loss of the normal enhancement of contractility and associated activation of adenyl cyclase after glucagon. This perhaps explains the inefficacy of this drug in treating patients with chronic cardiac failure.
Electrophysiologic Studies during Accelerated Idioventricular Rhythms
Authors: GALLAGHER JOHN J. , DAMATO ANTHONY N. , LAU SUN H.
Published: June 2012

Accelerated idioventricular rhythms (AIVR) are ectopic ventricular rhythms with rates intermediate between idioventricular escape rhythms (30 to 40/min) and ventricular tachycardia (120 to 180/min). Differentiation of AIVR from supraventricular arrhythmias rests primarily on demonstration of their ventricular origin. His bundle electrograms (HBE) were recorded in four patients during AIVR. HBE verified the idioventricular nature of the ectopic rhythm and excluded supraventricular rhythm with aberration as a cause. In addition, they permitted the recognition of normally conducted sinus beats, fusion beats, and idioventricular beats. The pacemaker site for the AIVR was below the bundle of His. AIVR became manifest when the heart rate was slowed by increasing vagal tone, premature atrial stimulation, and high degree atrioventricular (A-V) block. AIVR could be suppressed and 1:1 A-V conduction established by increasing the atrial rate with atropine or by atrial pacing.
Lown-Ganong-Levine Syndrome
Authors: MANDEL WILLIAM J. , DANZIG RONALD , HAYAKAWA H.
Published: June 2012

His bundle recordings were obtained in three patients with histories of recurrent supraventricular tachycardias and electrocardiograms demonstrating a short P-R interval with a normal QRS (the Lown-Ganong-Levine syndrome). The His bundle electrograms obtained during sinus rhythm demonstrated a normal A-H (atrium-to-His bundle) time in one patient and a low normal A-H time in two patients. The H-V (His bundle-to-ventricle) time was short in all three patients. Atrial pacing in two patients produced an attenuated degree of prolongation of the A-H time without a change in conduction distal to the proximal His bundle. The probable mechanisms of accelerated conduction in these three patients include: (1) partial A-V nodal bypass via (a) the posterior intenodal tract or (b) functional bypass fibers within the A-V node; and (2) accelerated conduction within the A-V conduction system distal to the A-V node.
Pathologic Changes in Aortic-Coronary Arterial Saphenous Vein Grafts
Authors: VLODAVER ZEEV , EDWARDS JESSE E.
Published: June 2012

This is a pathologic study of segments of saphenous vein used as a graft between the aorta and a coronary artery in the surgical treatment of coronary atherosclerosis. Except for an occasional case with thrombotic occlusion of the graft, no lesions were observed in grafts which had been in place for less than 1 month. In each of two grafts in place for 1 month, mild fibrous thickening of the intima was present. Eight grafts which had been in place for 3½ months or longer consistently showed lesions, either organized thrombi (two grafts) or intimal fibrotic proliferative lesion (six grafts). In this group, five of the six grafts with intimal fibrous proliferation showed near or complete occlusion of the lumen.

The intimal fibrous proliferative lesion appears primarily to be a response to arterial pressure within the segment of vein. Obstructive atherosclerosis in the artery beyond the anastomosis with the graft may favor the development of the intimal lesion. The intimal lesion may progress rapidly according to the data in one of the cases. In this, patency of the graft demonstrated angiographically 3½ months after the operation was followed by near-complete occlusion of the lumen by the proliferative lesion 3 weeks following demonstration of patency.
Hypoplasia of the Inflow Portion of the Right Ventricle: An Angiocardiographic Sign of Tricuspid Atresia
Authors: BARON MURRAY G.
Published: June 2012

Atresia of the tricuspid valve is constantly associated with a large interatrial communication and an underdeveloped right ventricle. The ventricle adjacent to the right atrium is usually represented by a solid mass of myocardium without a lumen and, therefore, remain unopacified on an angiocardiogram. The resulting triangular lucency between the contrast-filled right atrium and left ventricle is the angiocardiographic hallmark of tricuspid atresia.
Acute Changes in Left Ventricular Volume and Contractility during Ventricular Pacing in Patients with Complete Heart Block
Authors: GOBEL FREDARICK L. , JORGENSEN CHARLES R. , KITAMURA KAZUTO , WANG YANG
Published: June 2012

To determine whether changes in preload and contractility may account for clinical improvement in patients with complete heart block (CHB) when the ventricular rate is increased by pacing, 10 hemodynamic studies were performed in nine patients with CHB. Left ventricular end-diastolic volume (EDV) was measured before and during pacing by the dye-dilution and the angiographic techniques. Changes in contractility were assessed from the first derivative of ventricular pressure divided by a common peak isovolumic pressure (CPIP) to correct for afterload and by EDV to correct for preload. EDV decreased during pacing, the mean value decreasing from 242 to 180 ml (
P
< 0.001). Since the left ventricular dp/dt is influenced by afterload and preload, improvement in contractility indices was consistent only after allowances were made for changes in aortic diastolic pressure and EDV. The mean dp/dt/CPIP divided by EDV increased from 0.120 to 0.160 (
P
< 0.005). The mean left ventricular enddiastolic pressure decreased from 17.0 to 9.7 mm Hg (
P
< 0.05) during pacing, while the mean cardiac index increased from 2.0 to 2.5 liters/min/m
2
(
P
< 0.025). The clinical improvement seen after pacing in patients with CHB results, in part, from an increase in contractility and a decrease in EDV and pressure.
Sinoatrial-Node Entrance Block
Authors: GOLDREYER BRUCE N. , DAMATO ANTHONY N.
Published: June 2012

Sinus-node function was characterized in 13 patients during cardiac catheterization by the introduction of progressively premature atrial depolarizations. Curves relating the extent of sinus-node depression following these premature depolarizations and their degree of prematurity were constructed. The maximum extent of sinus-node depression following premature depolarizations and A-V-nodal and atrial refractoriness were determined. Maximum sinus-node depression could be demonstrated to be independent of sinus rate. In six patients "early" atrial premature depolarizations demonstrated entrance block into the sinus-node pacemaker. Sinoatrial (SA) node entrance block could be clearly distinguished from atrial echoes and repetitive atrial firing subsequent to stimulation during the atrial relative refractory period. Prolonged refractoriness of tissues conducting impulses between atrium and sinus node was unrelated to parameters of sinus-node automaticity (sinus rate or maximum depression following premature atrial depolarizations) or to the refractoriness of the atrium itself.
Aortocoronary Bypass Graft
Authors: GRONDIN CLAUDE M. , LEPAGE GILLES , CASTONGUAY YVES R. , MEERE CLAUDE , GRONDIN PIERRE
Published: June 2012

Intraoperative measurements of blood flow were made in 70 patients in whom a total of 103 venous bypass grafts had been inserted from the aorta to the right, the left anterior descending, or the circumflex coronary artery. Cineangiographic evaluation of graft patency was performed in all patients. Overall patency rate was 90.3%. Flow in all bypass grafts averaged 68 ml/min. All grafts with flow of 20 ml or less or which failed to respond to the injection of 20 mg of papaverine became occluded. All grafts with flow greater than 45 ml/min remained open.
Occurrence of Ventricular Arrhythmias with Exercise as Compared to Monitoring
Authors: KOSOWSKY BERNARD D. , LOWN BERNARD , WHITING RICHARD , GUINEY TIMOTHY
Published: June 2012

Treadmill exercise testing and prolonged ambulatory electrocardiographic monitoring were compared for their ability to reveal ventricular ectopic activity in 81 patients. Both proved more effective than a 3-minute standard electrocardiogram (ECG) in displaying ventricular arrhythmias. Of 66 patients in whom the resting ECG was normal, prolonged monitoring was positive for arrhythmia in 18, or 27%, whereas exercise was positive in 26, or 39%. In 12 cases ventricular arrhythmia was recorded only with exercise. In addition to displaying an increased incidence of arrhythmia, exercise also revealed more serious rhythm abnormalities which would not have been suspected on monitoring alone. This was true in patients with and without coronary heart disease (CHD). Thus, exercise is an effective means of eliciting suspected arrhythmias. The prognostic significance of exercise-induced arrhythmias in patients with CHD remains to be determined.
Effects of Ouabain on Impaired Left Ventricular Function during Convalescence after Acute Myocardial Infarction
Authors: RAHIMTOOLA SHAHBUDIN H. , DIGILIO MICHAEL M. , SINNO M. ZIAD , LOEB HENRY S. , ROSEN KENNETH M. , GUNNAR ROLF M.
Published: June 2012

The effects of intravenous ouabain (0.015 mg/kg body weight) were assessed in 13 patients 3-5 weeks after an uncomplicated acute myocardial infarction. The patients were not in clinical cardiac failure and were not having anginal pain.

The mean ±
sem
of the values prior to (C) and 1 hour after ouabain (A) were: left ventricular end-diastolic pressure (LVEDP), C 18.6 ± 1.5, A 10.2 ± 1.4; stroke index, C 35.8 ± 3.9, A 39.5 ± 4.8; left ventricular stroke work (LVSW), C 99.4 ± 15.8, A 120.3 ± 19.5; mean rate of LV ejection (MRE), C 237.3 ± 21.9, A 274.5 ± 28.9; peak LV dp/dt, C 1,614 ± 141, A 2,145 ± 230; preejection period corrected for heart rate (PEP
c
), C 135.8 ± 8.7, A 125.1 ± 9.2; left ventricular ejection time corrected for heart rate (LVET
C
), C 407.9 ± 10.3, A 389.5 ± 9.2. These changes were significant (
P
< 0.05 for paired determinations). There were no significant changes in cardiac index, heart rate, mean arterial pressure, and systemic resistance.

The reductions of LVEDP, PEP
c
, and LVET
c
and increases in SI, LVSW, MRE, and peak LV dp/dt show improvement of ventricular performance after ouabain and suggest that digitalis therapy could contribute to the management of patients convalescing after uncomplicated acute myocardial infarction.
Incidence of Myocardial Infarction and Sudden Death from Coronary Heart Disease in Nashville, Tennessee
Authors: HAGSTROM RUTH M. , FEDERSPIEL CHARLES F. , HO YAW CHIN
Published: June 2012

The incidence rates for myocardial infarction and sudden death attributable to coronary heart disease for adults between the ages of 35 and 74 years for black and white populations were studied in Nashville, Tennessee, for a l-year period, July 1, 1967 to June 30, 1968. The overall incidence rate for myocardial infarction was 3.42 and for sudden coronary death, 1.55 per 1,000 population. The male-to-female ratio for the white population for myocardial infarction was 3:1, and for the black population 2:1. Similar male-to-female ratios were found for those dying suddenly for both races. However, both black males and females died suddenly at a higher rate than did the white.

Over half of the sudden deaths occurred within a 2-hour period after onset of symptoms. Fifty-two percent were dead on arrival at a hospital, 31% died at home, and 6% in a public place. Only 4% had either no contact with a source of medical care or had negative disease histories prior to sudden death. Thus, it would seem possible in further studies to identify a group of individuals at high risk of sudden death from coronary heart disease.
Role of Echocardiography in Diagnostic and Hemodynamic Assessment of Hypertrophic Subaortic Stenosis
Authors: SHAH PRAVIN M. , GRAMIAK RAYMOND , ADELMAN ALLAN G. , WIGLE E. DOUGLAS
Published: June 2012

An abnormal sharp anterior motion of the anterior mitral leaflet has been previously described as a diagnostic abnormality in hypertrophic subacute stenosis (HSS). The present prospective study explored the diagnostic sensitivity and specificity of this finding in 26 patients studied without knowledge of clinical diagnosis. When the abnormality observed was complete and persistent, a correct diagnosis of HSS was made in every case. In the absence of systolic abnormality at rest and on provocation, the diagnosis of HSS could be excluded. When the abnormality was small and inconstant (nine patients) two thirds of the patients were shown to have a latent or labile form of outflow obstruction whereas the remaining third had no evidence of HSS.

In an extended part of the study on 31 patients with known HSS, comparisons of resting pressure gradients across left ventricular outflow tract were made with the echocardiographic findings at rest. Those with persistently abnormal mitral valve movement had an average pressure gradient of 78 mm Hg, those with inconstant abnormality had an average gradient of 24 mm Hg, and those with no resting abnormality had no gradients at rest.
Quantification of Left Heart Volume and Systolic Output in Transposition of the Great Arteries
Authors: GRAHAM THOMAS P. , JARMAKANI JAY M. , CANENT RAMON V. , JEWETT PAUL H.
Published: June 2012

Left heart volume and output were calculated by using cineangiocardiograms from 64 studies in 44 patients with transposition of the great arteries (TGA). The majority of patients who had an intact ventricular septum and were less than 6 months of age showed normal end-diastolic volumes (LVEDV) and systolic output (LVSO), while patients in this hemodynamic group more than 6 months of age had elevated volumes and outputs. The presence of a patent ductus arteriosus (PDA) was associated with an increase in LVEDV and LVSO. Patients with a ventricular septal defect (VSD) and no pulmonary stenosis (PS) had increased volumes and outputs with the average values for LVEDV and LVSO significantly greater for the VSD group than for the intact-septum group. Patients with a VSD and PS showed normal values for LVEDV and LVSO. The ejection fraction was normal in all patients. Left atrial maximal volume (LAMax) was normal in the majority of patients with an intact ventricular septum and no PDA, but was increased in patients with a VSD and no PS. The values for LVEDV, LVSO, and LAMax showed little or no change following balloon atrial septostomy in the majority of patients. Four patients studied before and after corrective surgery demonstrated decreases in LVEDV and LVSO to normal values following successful interatrial venous transposition. Left heart volume variables derived from cineangiocardiograms can aid considerably in hemodynamic evaluation of patients and in estimation of pulmonary blood flow.
Double-Lumen Flotation Catheter for Use in Complex Congenital Cardiac Anomalies
Authors: KELLY DAVID T. , KROVETZ L. JEROME , ROWE RICHARD D.
Published: June 2012

The use of the Swan-Ganz flow-directed right heart catheter should be a considerable aid in obtaining diagnostic information in complex congenital heart disease. It is safe and requires little technical expertise. Its use should decrease considerably the amount of radiation exposure to both patient and operator.
Surgical Considerations of Ventricular Septal Defect Associated with Complete Transposition of the Great Arteries and Pulmonary Stenosis
Authors: IMAMURA E. S. , MORIKAWA TETSUO , TATSUNO KATSUHIKO , KONNO SOUJI , ARAI TATSUTA , SAKAKIBARA SHIGERU
Published: June 2012

Ventricular septal defect (VSD) associated with complete transposition of the great arteries was studied, and each of the typical anatomic varieties was depicted to emphasize the characteristic features of the VSD. Among the 32 specimens, 13 cases were found to have a VSD lying anterosuperior to the origin of the papillary muscle of the conus, indicating that repair of the VSD could be performed without difficulty. Such a defect situated above the crista supraventricularis has proved to be technically most preferable, as shown in the case report. In contrast, the remaining 19 cases appeared to be inappropriate for the technique, as the VSD was overhung by a part of the tricuspid valve. Additional analysis was made of the angiocardiographic appearances of the VSD, demonstrating some characteristic patterns.
Left Anterior Oblique View for Evaluation of Left Atrial Size
Authors: BARON MURRAY G.
Published: June 2012

The left anterior oblique film of the chest provides a sensitive and accurate gauge of left atrial enlargement. The posterior wall of the atrium, which distends when the chamber enlarges, is seen in profile in this view. Dilatation of the left atrium is almost always reflected by this segment which assumes a convexly, curved contour. This finding is independent of most of the conditions that can alter the other roentgen signs of left atrial enlargement.
The Cardiomyopathies—Current Perspectives
Authors: PERLOFF JOSEPH K.
Published: June 2012

This paper is designed to provide a contemporary overview of primary myocardial disease. The cardiomyopathies are dealt with in the light of both pathophysiologic and etiologic classifications. A relatively simple diagnostic approach is based upon these classifications together with the clinical manifestations of the cardiomyopathies. The essential principles of the natural history are summarized, and treatment is dealt with in terms of specific curatives, general pharmacologic measures, and management of factors that modify, aggravate, or contribute to the development of primary myocardial disease.
Virus and the Heart
Authors: ABELMANN WALTER H.
Published: June 2012

Viral infections may overload the heart by altering pulmonary or systemic vascular resistance, may induce congenital malformations, or may invade the mature heart muscle and provoke acute and possibly chronic myocarditis. The nature of the association of myocarditis with known viral infections and the pathophysiologic effects of myocardial involvement are analyzed. Although viral myocarditis of clinical significance is relatively rare, recent advances in diagnosis and therapy warrant greater dissemination and application of existing knowlelge as well as further clinical investigation.
Ethyl Alcohol and the Heart
Authors: REGAN TIMOTHY J.
Published: June 2012

Since a significant fraction of the population are heavy consumers of ethanol, and recent postmortem studies suggest that most alcoholics have some degree of cardiac abnormality, elucidation of the basis for alcoholic cardiomyopathy is of some importance. Intoxicating amounts of ethanol depress ventricular function acutely and effect leakage of myocardial cell components.

On the basis of studies in three animal species and in man, it would appear that the cumulative effects of chronic ethanol intake can, without evident malnutrition, depress ventricular function and produce metabolic and morphologic abnormalities of the myocardium before clinical manifestations. Progression of the disease to produce heart failure, arrhythmias, or thromboembolism, separately or in combination, occurs under multiple circumstances that are not clearly defined. These would appear to include the cumulative effects without superimposed factors, an intensified drinking episode, simultaneous exposure to trace metals in excess, and occasional specific nutritional deficiency or superimposed infection. The low incidence of nutritional complications such as cirrhosis, peripheral neuritis, and delirium tremens associated with cardiomyopathy supports the view that the cardiac abnormality is commonly not dependent on malnutrition. Finally, clinical data indicate that cessation of alcohol intake will reverse the disease or interrupt its progression in many patients. Anticoagulant therapy is recommended at least during the early recovery stage.
Hemodynamic Effects of Exercise in Isolated Valvular Aortic Stenosis
Authors: BACHE ROBERT J. , WANG YANG , JORGENSEN CHARLES R.
Published: June 2012

Hemodynamic data, including simultaneously measured left ventricular and aortic pressures, were obtained from 20 patients with isolated valvular aortic stenosis at rest and during supine leg exercise. Changes in left ventricular end-diastolic pressure during exercise were not significantly related to the severity of aortic stenosis but were correlated with age; patients with abnormal left ventricular end-diastolic pressures during exercise were significantly older than those in whom this variable remained normal. Exercise resulted in significant increases in both the mean rate of systolic aortic blood flow and the mean systolic pressure gradient across the aortic valve. Analysis of this pressure gradient demonstrated symmetrical shortening of the ejection time per beat with an increase of the maximal systolic pressure gradient during exercise. Although changes in mean systolic aortic pressure gradient and mean aortic flow were significantly positively correlated, the increases in mean systolic pressure gradient during exercise were less than predicted from corresponding increases in mean aortic flow; thus the result was an apparent increase in computed aortic valve area.
Evaluation of Left Ventricular Contractile State in Childhood
Authors: GRAHAM THOMAS P. , JARMAKANI JAY M. , CANENT RAMON V. , ANDERSON PAGE A. W.
Published: June 2012

Left ventricular contractile state was evaluated in 20 children ages 3 to 11 years with normal left hearts and in 15 children ages 2 to 16 years with a left ventricular pressure overload. All patients were studied during diagnostic cardiac catheterization with catheter-tip micromanometry. Pressure-velocity curves were obtained during isovolumic systole by plotting (dp/dt)/28 P versus developed or total pressure (P). Computer analysis of five cardiac cycles was used to yield one composite pressure-velocity curve for each patient with both linear and second-degree polynomial curve analysis. The developed pressure method yielded higher values for the calculated V
max
index, (dp/dt)/28 P at zero P than the total-pressure method for all patients. Normal standards were defined for both methods. The V
max
index calculated with total pressure as well as peak (dp/dt)/28 P was significantly less than normal for the hypertrophy group. The V
max
index calculated with developed pressure was not significantly different from normal for the entire hypertrophy group, but four of the 15 patients showed a depression of contractile state defined as a value for the V
max
index less than 2
sd
of normal. These results indicate the potential importance of preoperative and postoperative estimation of contractile state in patients with a left ventricular pressure overload in evaluation of possible irreversible alterations of contractility that may accompany myocardial hypertrophy.
Electrophysiologic Studies on Mobitz Type II Second-Degree Heart Block
Authors: SPEAR JOSEPH F. , MOORE E. NEIL
Published: June 2012

Experimental studies were carried out in animals with intracellular and extracellular electrodes used to record simultaneously from the atrium, atrioventricular (A-V) node, bundle of His, bundle branches, Purkinje fibers, and ventricles to determine the site of conduction delay and block in Mobitz type II second-degree heart block. Type II block with block occurring within the His-Purkinje system was observed only rarely in normal animals; however, Mobitz type II block could be induced in normal hearts by slight but undetectable variations in the P-P interval. Sudden conduction failure was usually due to block within the His-Purkinje system. Type II block also resulted from failure of conduction within the A-V node during depressed A-V conduction due to rapid atrial pacing, vagal stimulation, or ouabain infusion. The classification of second-degree heart block according to Mobitz type I (increasing P-R interval) and Mobitz type II (constant P-R interval) block should take into account that the site of block in both cases can occur either in or below the A-V node. Admittedly, in man Mobitz type I block is most often intranodal while type II block is usually infranodal following myocardial infarction. His bundle electrocardiography may therefore be indicated to determine the site of block in patients with Mobitz type II block, particularly in those with prolonged P-R intervals.
Right Aortic Arch
Authors: BARON MURRAY G.
Published: June 2012

A right aortic arch usually produces several abnormal shadows on a standard frontal film of the chest. The aortic knob protrudes from the right side of the mediastinum, the trachea is deviated to the left, and the descending aorta can be identified along the right side of the spine. A more conclusive diagnosis can be made from the indentation produced by the arch on the barium-filled esophagus. This also serves to distinguish the two types of right aortic arch. The presence of a large indentation on the posterior aspect of the esophagus is characteristic of the type of arch most frequently associated with a vascular ring. A right arch without a posterior component is commonly associated with significant congenital heart disease.
Effects of Ouabain on Myocardial Potassium and Sodium Balance in Man
Authors: BRENNAN F. JAMES , MCCANS JOHN L. , CHIONG MIGUEL A. , PARKER JOHN O.
Published: June 2012

Myocardial electrolyte balance and hemodynamics were studied in 14 patients before and after the administration of ouabain. The drug caused a significant loss of potassium from the myocardium. This was accompanied by a significant positive inotropic response, indicated by an increase in the rate of rise of left ventricular pressure and systolic ejection-rate index. Heart rate, cardiac output, left ventricular end-diastolic pressure, brachial artery pressure, and left ventricular stroke-work index remained unchanged. These observations in man are compatible with those theories of digitalis action which associate inotropic effect with the inhibition of membrane sodium- and potassium-activated adenosine triphosphatase.