bluuebunny/crossref_metadata_2025 huggingface dataset:
Echocardiographic observations on the mechanism of production of the second heart sound.
Authors: Chandraratna P A , Lopez J M , Cohen L S
Published: June 2012

This investigation was designed to determine the echocardiographic correlates of the aortic and pulmonary components of the second heart sound. Simultaneous recordings of the ECG, phonocardiogram, carotid pulse tracing and the echocardiogram of the aortic valve were made in 54 patients. The tracings were recorded at a paper speed of 100 mm/sec, with 20 msec time lines. Aortic valve closure (AVC) on the echocardiogram occurred before the onset of the aortic component of the second heart sound (A2) in all but two patients. The mean AVC-to-A2 interval was 12 msec with a range of 5 to 25 msec. Simultaneous recordings of the pulmonary valve echocardiogram, ECG, phonocardiogram and carotid pulse tracing were made in 14 patients. Pulmonary valve closure (PVC) on the echocardiogram preceded the pulmonary component of the second sound (P2) in all patients. The mean PVC-2 interval was 60 msec with a range of 30 to 75 msec. We conclude that aortic valve closure and pulmonary valve closure are not directly responsible for the genesis of the second heart sound (S2). These observations are consonant with the theory that S2 is caused by deceleration of columns of blood resulting from semilunar valve closure, throwing the cardiohemic system into vibration.
Hemodynamic features of prolapsing and nonprolapsing left atrial myxoma.
Authors: Sung R J , Ghahramani A R , Mallon S M , Richter S E , Sommer L S , Gottlieb S , Myerburg R J
Published: June 2012

In the course of the evaluation of five patients with left atrial myxoma, it was noted that the movement of the myxoma was related to specific changes in left atrial hemodynamics. Prolapsing tumors, Type I, move from the left ventricle to the left atrium in early systole and from the left atrium to the left ventricle in early diastole, thereby causing prominent c and v waves accompanied by a rapid y descent. Nonprolapsing tumors, Type II, remain in the left atrium during the entire cardiac cycle, impeding flow across the mitral valve. In these latter cases, the y descent is slow and indistinguishable from that caused by mitral valvular stenosis. The cineangiocardiograms and echocardiograms corroborate these two types of hemodynamic observations. The particular value of direct echocardiographic examination of the left atrium prior to cardiac catheterization was evident in two of the three patients with nonprolapsing tumors. Since the hemodynamic pattern of nonprolapsing left atrial myxoma resembles that of mitral valvular stenosis, it is stressed that echocardiography should have an important place in precatheterization assessment of patients with mitral valve disease. If left atrial myxoma is suspected clinically or on the basis of echocardiographic findings, regardless of the pressure curve contours, transseptal cardiac catheterization should be avoided and the left atrium visualized by pulmonary angiography levophase.
The deceptive aortic root.
Authors: Viamote M , Camacho M , Cahill D R , Viamonte M , Mori K
Published: June 2012

Coronal, horizontal, and sagittal sections through the mid-line are excellent ways of depicting the anatomical position of the aortic root and for studying its topographical relationship to the surrounding vascular structures. Minimal radiographic abnormalities or no abnormalities at all may be present with an enlarged ascending portion of the thoracic aorta. Thus, frontal chest roentgenograms obtained with high kilovoltage, fluoroscopy and left anterior oblique projections should be utilized routinely for the evaluation of the ascending aorta. Calcification of the aortic valve and of the coronary arteries and the study of aortic valve prosthesis also demand a dynamic study and the use of complementary views, such as lateral and both oblique projections.
The course of acute myocardial infarction. Feasibility of early discharge of the uncomplicated patient.
Authors: McNeer J F , Wallace A G , Wagner G S , Starmer C F , Rosati R A
Published: June 2012

This report represents our experience with 522 consecutive patients with acute myocardial infarction admitted directly to the Duke Coronary Care Unit. Fifty items of information were used to characterize the patients, their hospital course and follow-up. Serious complications included death, ventricular tachycardia or fibrillation, second- or third-degree heart block, pulmonary edema, cardiogenic shock, persistent sinus tachycardia or hypotension, atrial flutter or fibrillation, and extension of infarction. Forty-nine percent of the patients (252 of 522) experienced a serious complication. All patients who experienced any serious complications had at least one of the above during the first four days of hospitalization. Patients who survived through day 4 were subgrouped on the basis of the occurrence (complicated) or lack of occurrence (uncomplicated) of the above on day 5. Complicated patients had a subsequent hospital mortality of 14% and an incidence of late serious complications of 51%. Patients who were uncomplicated through day 4 had a subsequent hospital mortality of zero and an incidence of late serious complications of zero. These data suggest that it would be feasible and ethically justified to conduct a prospective clinical trial of early discharge (7th day) in patients who meet the above criteria for uncomplicated. The potential economic savings through earlier discharge in uncomplicated patients are of major significance.
Three variants of concealed bigeminy.
Authors: Levy M N , Adler D S , Levy J R
Published: June 2012

Long electrocardiographic strips were analyzed from five patients who exhibited periods of typical "concealed bigeminy," i. e., recurrent unifocal extrasystoles which were separated from one another by odd numbers of normally conducted sinus beats. However, in each of these patients, there were periods in which one of three different variants of concealed bigeminy was observed. Three patients displayed an "even number" variant; i. e., there were large numbers of consecutive extrasystoles which were separated exclusively or preponderantly by even rather than by odd numbers of sinus beats. One other patient exhibited an "interpolated extrasystole" variant: those interectopic intervals which were initiated by an interpolated extrasystole contained an even number of sinus beats, whereas all other interectopic intervals contained an odd number. In the fifth patient, the distribution of the numbers of sinus beats separating extrasystoles was such as to suggest a periodic fluctuation between the classical forms of concealed bigeminy and concealed trigeminy; i. e., a "combined bigeminy and trigeminy" variant.
Augmentation of myocardial digoxin concentration in hemorrhagic shock.
Authors: Lloyd B L , Taylor R R
Published: June 2012

The effect of the shock state on myocardial digoxin uptake and plasma digoxin levels was examined in unanesthetized dogs following hemorrhage. Five minutes after intravenous administration of tritiated digoxin the myocardial digoxin content in animals with shock was greater than in normal animals in both left ventricle (LV) (165 plus or minus 15 (SD) ng/g vs 130 plus or minus 26 ng/g, P smaller than 0.02 and right ventricle (RV) (142 plus or minus 13 ng/g vs 111 plus or minus 22 ng/g. P smaller than 0.02) as was the plasma digoxin concentration (61.6 plus or minus 11.8 ng/ml vs 44.3 plus or minus 4.6 ng/ml, P smaller than 0.02). After one hour, in another group of dogs, the difference in myocardial concentration of digoxin between test and normal groups was even greater (LV: 213 plus or minus 26 ng/g vs 133 plus or minus 13 ng/g, P smaller than 0.001; RV: 171 plus or minus 9 ng/g vs 111 plus or minus 8 ng/g. P smaller than 0.001) despite lower plasma digoxin concentration in the test group (12.9 plus or minus 2.9 ng/ml vs 17.3 plus or minus 2.5 ng/ml, P smaller than 0.05). Diminished peripheral blood flow, peripheral digoxin delivery and uptake were probably responsible for the early difference in plasma digoxin levels. Resultant greater plasma concentrations of digoxin presented to the myocardium in the early phase, coupled with relative preservation of myocardial blood flow, may explain the greater myocardial uptake in animals with shock although myocardial mechanical factors may also be implicated. Augmented uptake of digoxin by the myocardium in canine hemorrhagic shock may be relevant to the altered susceptibility to glycoside action in clinical shock syndromes.
Echocardiographic demonstration of early mitral valve closure in severe aortic insufficiency. Its clinical implications.
Authors: Botvinick E H , Schiller N B , Wickramasekaran R , Klausner S C , Gertz E
Published: June 2012

Severe aortic insufficiency may accelerate mitral valve closure. We noted this echocardiographic finding in several patients with the acute onset of severe aortic insufficiency. Accordingly, we examined our total echocardiographic series retrospectively for early closure of the mitral valve (ECMV) in the setting of aortic insufficiency and found it in 11 of 53 patients with confirmed aortic insufficiency. During our study ECMV was fortuitously found in two other patients without aortic insufficiency, ECMV occurred in late diastole following the echocardiographic "A" wave, often associated with s suppressed "A" wave (type "B" ECMV). ECMV presence and subtype, along with other clinical parameters, appeared to be useful in the serial evaluation of the patient with severe aortic insufficiency. Additionally, the analysis of ECMV type helped to clarify the mechanism and significance of the Austin Flint murmur. Analysis of 17 patients with and without ECMV, with severe aortic insufficiency judged clinically (NYHA functional class III or IV) and angiographically (3+), indicated that only ECMV patients had acute aortic insufficiency and demonstrated diminished left ventricular size following successful aortic valve replacement. Although due primarily to aortic insufficiency, ECMV could be influenced by rhythm or conducted abnormalities, co-existent cardiac lesions, and pharmacologic interventions. Exclusive of these factors, ECMV was an excellent sign of acute, torrential aortic insufficiency, and a simple noninvasive indicator of the patient requiring immediate aortic valve replacement.
Radionuclide angiocardiography. Improved diagnosis and quantitation of left-to-right shunts using area ratio techniques in children.
Authors: Alderson P O , Jost R G , Strauss A W , Boonvisut S , Markham J
Published: June 2012

A comparison of several reported methods for detection and quantitation of left-to-right shunts by radionuclides was performed in 50 children. Count ratio (C2/C1) techniques were compared with the exponential extrapolation and gamma function area ratio techniques. C2/C1 ratios accurately detected shunts and could reliably separate shunts from normals, but there was a high rate of false positives in children with valvular heart disease. The area ratio methods provided more accurate shunt quantitation and a better separation of patients with valvular heart disease than did the C2/C1 ratio. The gamma function method showed a higher correlation with oximetry than the exponential method, but the difference was not statistically significant. For accurate shunt quantitation and a reliable separation of patients with valvular heart disease from those with shunts, area ratio calculations are preferable to the C2/C1 ratio.
Hypotension accompanying the onset of exertional angina. A sign of severe compromise of left ventricular blood supply.
Authors: Thomson P D , Kelemen M H
Published: June 2012

Serious obstructive coronary artery disease was found in all patients who developed hypotension accompanying the onset of angina during multistage exercise testing. Seventeen exercising patients demonstrated a fall in systolic pressure to below resting levels as chest pain and ST-segment depression appeared. Two patients died suddenly six weeks after treadmill testing and prior to arteriography. The remaining fifteen were studied with coronary arteriography and all except one exhibited greater than or equal to 90% stenosis of the left anterior descending artery (LAD). The remaining patient demonstrated two 75% LAD stenoses in series. Five exhibited significant (greater than or equal 75%) narrowing of the main left coronary artery (MLCA) and thirteen of fifteen had significant stenosis of proximal LAD and circumflex arteries. The two patients without significant circumflex disease exhibited greater than or equal to 90% stenosis of the dominant right coronaryartery (RCA) circulation. Six of six patients had restoration of a normal blood pressure response following coronary bypass surgery, which also relieved angina and reversed ST-segment depression. Conditions essential for proper interpretation of this sign are discussed. If these conditions are met, then a fall in systolic pressure during treadmill-induced angina pectoris is a reliable sign of severe compromise of left ventricular blood supply.
Prinzmetal's variant form of angina pectoris. Re-evaluation of mechanisms.
Authors: Endo M , Kanda I , Hosoda S , Hayashi H , Hirosawa K , Konno S
Published: June 2012

Thirty-five patients with typical Prinzmetal's variant angina were studied by coronary cineangiography. There was no demonstrable stenosis of the major coronary arteries in 19 patients. Nine patients with single coronary stenosis underwent aortocoronary bypass and had recurrence of the symptoms postoperatively. Administration of nifedipine effected complete cessation of the symptoms among patients formerly treated medically. Although surgical treatment did not effect permanent relief of pain, all patients initially treated surgically experienced relief of pain when nifedipine was administered. The pathophysiology of variant angina remains obscure. Our results suggest that neurohumoral factors exert more of an effect on the myocardial cell than on the coronary vessels.
Regional myocardial blood flow measurements before and after coronary bypass surgery. A preliminary report.
Authors: Korbuly D E , Formanek A , Gypser G , Moore R , Ovitt T W , Tuna N , Amplatz K
Published: June 2012

Myocardial blood flow in 16 patients before and after coronary bypass surgery in conjunction with coronary angiography, left ventricular function measurement, and graded exercise test. Radioactive 133-Xe was injected into the coronary artery or bypass graft and the washout was recorded by an Anger camera. Myocardial blood flow increased in 11 out of 14 patients and decreased in three patients. The average flow was 55 (plus or minus 6) preoperatively and 96 (plus or minus 10) ml 100 g/min postoperatively. Increase of blood flow occurred in both the bypassed left anterior descending coronary artery (LAD) region and the nonbypassed left circumflex coronary artery (LCIR) region. The postoperative flow increase and the absolute postoperative flow values are higher with saphenous vein than with mammary artery grafts. Statistically significant correlation is not found between myocardial blood flow changes and exerice tolerance. The volume measurements (end diastolic volume, stroke volume, ejection fraction) remained unchanged.
Coronary ostial stenosis.
Authors: Pritchard C L , Mudd J G , Barner H B
Published: June 2012

Symptomatic, nonsyphilitic, acquired coronary ostial stenosis is a rare angiographic finding and was found in 0.13% of 3000 coronary angiograms. Three females with this lesion have been treated surgically. Two had left coronary ostial involvement. Coronary angiography may result in catheter tip occulsion of the ostium with chest pain, dyspnea, diaphoresis, systemic hypotension and abrupt fall in pressure at the catheter tip. Recognition of this entity is necessary for safe coronary angiography. Involvement of the left ostium carries the same serious prognosis as does left main coronary disease.
Arrhythmias in patients with mitral valve prolapse.
Authors: Winkle R A , Lopes M G , Fitzgerald J W , Goodman D J , Schroeder J S , Harrison D C
Published: June 2012

Resting ECGs, exercise treadmill tests and 24-hour ambulatory ECGs were recorded and analyzed in 24 unselected patients with mitral valve prolapse. Arrhythmias were frequent. There were three distinct groups of patients, defined on the basis of total number of premature ventricular contractions (PVCs) during the 24 hours; there were no PVCs in 25%, and frequent PVCs in 50%. Complex ventricular arrhythmias, including ventricular tachycardia in five patients, were found almost exclusively in the group with frequent PVCs. Fifteen of the 24 patients demonstrated atrial premature contractions (APCs) during the 24 hours. Complex atrial arrhythmias were found among patients with infrequent, as well as those with frequent, APCs. Supraventricular tachycardia was detected in seven of these patients. The incidence of ACPs decreased during sleep in 67% of the patients and showed no change during sleep in 33%. A poor correlation was found between symptoms recorded in patient diaries and changes noted on 24-hour ECG recordings. The peak PVCs/15 min and peak ACPs/15 min during a 24-hour period of monitoring was found to be an excellent guide to the total number of PVCs and APCs occurring during that period. This permits an accurate prediction of the total number of PVCs in 24 hours after performing an exact PVC count on only 15 minutes of ECG data. Finally, the 24-hour ambulatory ECG was sensitive than the treadmill test and both were superior to the 12-lead ECG for detecting arrhythmias in these patients.
Right ventricular dysfunction detected by gated scintiphotography in patients with acute inferior myocardial infarction.
Authors: Rigo P , Murray M , Taylor D R , Weisfeldt M L , Kelly D T , Strauss H W , Pitt B
Published: June 2012

Twenty-seven patients with acute myocardial infarction not complicated by cardiogenic shock and ten normal volunteers were studied with gated cardiac blood pool scans. The ratio right vetricular area/left ventricular area (RVA/LVA) determined from the left anterior oblique end-diastolic scans was examined. The ratio was 1.11 +/- .06 in the normal volunteers. In patients with anterior infarction the ratio fell to 0.75 +/- .12 (P less than .05) due to left ventricular enlargement. In those with inferior infarction the ratio was 1.12 +/- .23 which was greater than in those with anterior infarction (P less than .05) due to enlargement of both the left and right ventricles. Six patients with cardiogenic shock, three with inferior and three with anterior infarction were studied. The three with anterior infarction had left ventricular enlargement and a decrease in the ratio of RVA/LVA to 0.62 while the three with inferior infarction had an increase in the ratio to 2.05 suggesting right ventricular dilatation and dysfunction. These studies suggest a high incidence of right ventricular dysfunction in patients with inferior myocardial infarction.
Reversal of dominance of the coronary arterial system in isolated aortic stenosis and bicuspid aortic valve.
Authors: Higgins C B , Wexler L
Published: June 2012

The dominance of the coronary arterial system was determined angiographically in 75 adult patients with isolated aortic stenosis with or without insufficiency, 25 adult patients with pure aortic insufficiency, 51 adult patients with combined aortic stenosis and mitral valve disease, and 44 children with bicuspid aortic valves. There was an unusually high incidence of left dominance in adults with isolated aortic stenosis (36%) and in children with bicuspid aortic valves (56.8%). These findings suggest the existence of a variant developmental complex consisting of a bicuspid aortic valve and reversal of dominance of the coronary arterial system. Furthermore, it adds support to the concept that progressive stenosis of a bicuspid aortic valve is frequently the etiology of isolated aortic stenosis in adults.
Inhibition of kinin formation by a kallikrein inhibitor during extracorporeal circulation in open-heart surgery.
Authors: Nagaoka H , Katori M
Published: June 2012

Involvement of the kinin system was studied in 58 patients during extracorporeal circulation in open heart surgery. At the onset of extracorporeal circulation, there was no increase of free kinin in blood and no reduction of plasma kininogen, when the latter was expressed as mug bradykinin/mg plasma protein. With the lapse of time, kinin in the blood increased significantly, and decrease of kininogen was also significant. The longer the circulation time, the greater the consumption of kininogen. The site of the kinin formation was presumed to be the heart-lung machine since the level of kinin increased slightly and kininogen decreased gradually in the blood leaving the machine, compared with those levels entering the machine. The difference in kininogen was significantly different from zero at termination of extracorporeal circulation. Administration of a kallikrein-trypsin inhibitor, trasylol (A. G. Bayer), infused into the heart-lung machine, prevented the decrease of kininogen. Reduction of the total peripheral resistance during this circulation was also prevented. The hemoconcentration, presumably the result of vascular permeability increase caused by increased kinin, was prevented by trasylol in cases in which extracorporeal circulation lasted over 60 minutes. Trasylol applied thus appears to be an effective counteragent for circulatory disturbances which occur during extracorporeal circulation.
Pulmonary edema during volume infusion.
Authors: Stein L , Beraud J J , Morissette M , Luz P D , Weil M H , Shubin H
Published: June 2012

The relationship between left ventricular filling pressure and plasma colloid osmotic pressure to pulmonary edema was examined in a group of 37 patients, the majority of whom were hypovolemic. Sixteen patients developed pulmonary edema during fluid infusion. In the 21 patients who did not develop pulmonary edema, the left ventricular filling pressure was slightly elevated but the colloid osmotic pressure was not reduced. The majority of these patients were treated with colloid solutions (group I). In five of the 16 patients who developed pulmonary edema, the left ventricular filling pressure was elevated and there was no reduction in the plasma colloid osmotic pressure. These patients received only colloids (group II). In the other 11 patients who developed pulmonary edema, the left ventricular filling pressure was normal but the plasma colloid osmotic pressure was reduced to 16 +/- 2 torr (group III). The colloid osmotic pressure in this group was significantly less than in the other two groups (P less than 0.01). Most of these patients received large volumes of crystalloid solutions. After administration of furosemide, clearing of pulmonary edema in this group was associated with normalization of the plasma colloid osmotic pressure. Infusion of large volumes of crystalloids in hypovolemic patients can be hazardous, for reduction of the plasma colloid osmotic pressure may predispose to the development of pulmonary edema even when the left ventricular filling pressure remains normal.
The role of sulfinpyrazone in the prevention of arterio-venous shunt thrombosis.
Authors: Kaegi A , Pineo G F , Shimizu A , Trivedi H , Hirsh J , Gent M
Published: June 2012

The effect of sulfinpyrazone on the incidence of thrombosis of arterio-venous shunts was investigated in a double-blind crossover study in 45 patients on chronic hemodialysis over a period of 12 months. The incidence of thrombosis was reduced from 0.64 thrombi per patient month when on placebo to 0.21 thrombi per patient month when on sulfinpryazone (P less than 0.001). The therapeutic effect was more striking in men than in women and became evident within a week of starting the drug. The side effects were minimal, requiring withdrawal from the study of only one patient. This crossover study strengthens the findings in the previous report that sulfinpyrazone is of value in the prevention of thrombosis.
A comparative analysis of antegrade and retrograde conduction patterns in man.
Authors: Akhtar M , Damato A N , Batsford W P , Ruskin J N , Ogunkelu J B
Published: June 2012

Patterns of antegrade and retrograde conduction and refractory periods were studied using His bundle electrogram recordings, incremental atrial and ventricular pacing and the extrastimulus technique. In 36/50 patients antegrade conduction was "better" than retrograde conduction (group I), as evidenced by a) onset of retrograde atrioventricular (A-V) nodal Wenckebach phenomenon at a slower rate compared to the antegrade counterpart (25 patients: group IA) or b) no ventriculo-atrial conduction at all ventricular paced rates (11 pts: group IB). The site of retrograde block in group IB patients was the A-V node. In eight patients (group II), antegrade and retrograde conduction appeared to be equal up to maximum paced rates of 160 beats/min. In six patients (group III) retrograde conduction was "better" than antegrade conduction, as indicated by onset of antegrade A-V nodal Wenckebach periods at slower rates than retrograde Wenckebach periods. During antegrade refractory period studies the area of maximum refractoriness was the A-V node in 19/40 patients, the His-Purkinje system (HPS) 6/40, and the atrial muscle in 15/40. During retrograde refractory period studies the A-V node was the area of maximum refractoriness in 12/36 pts (4/40 patients had A-V dissociation during ventricular pacing), the HPS in 12/36, and the ventricular muscle in 10/36. In 2/36 patients the site of maximum refractoriness retrogradely could not be determined: The area of maximum refractoriness during both antegrade and retrograde refractory period studies was the same in 11 patients (A-V node in seve and HPS in four), was different (i.e., A-V node or HPS) in 18 patients, and was the artrial or ventricular muscle in six patients. In five patients, including four patients in whom V-A conduction failed to occur, the above comparisons were not made. It is concluded that 1) antegrade conduction is better than retrograde conduction in most patients; 2) it is not always possible to predict area of maximum refractoriness during premature stimulation (both atrium and ventricle) from observations made during incremental pacing; 3) it is equally difficult to extrapolate patterns of retrograde conduction and refractory periods from results of antegrade conduction and refractory period studies.
Influence of acute alterations in heart rate and systemic arterial pressure on echocardiographic measures of left ventricular perfornmance in normal human subjects.
Authors: Hirshleifer J , Crawford M , O'Rourke R A , Karliner J S
Published: June 2012

To study the effects of acute alterations in heart rate and systemic arterial pressure on the mean velocity of left ventricular circumferential fiber shortening (Vcf) and on mean posterior wall velocity (Vpw), we performed ultrasound studies in 25 normal human subjects between the ages of 21 and 29 years. When heart rate was augmented by the administration of intravenous atropine from 64 +/- 2.2 (SEM) to 98 +/- 2.7 beats/min, mean normalized Vcf increased from 1.22 +/- 0.05 to 1.38 +/- 0.06 circumferences (circ)/sec(P less than 0.001). Mean normalized Vpw increased from 0.76 +/- 0.03 to 0.89 +/- 0.04 sec-1 (P less than 0.001). Mean Vcf and mean Vpw uncorrected for end-diastolic diameter increased in a similar fashion (P less than 0.01). After atropine administration, systemic arterial pressure was augmented by means of a phenylephrine infusion in 23 subjects by an average of 39 mm Hg (range 20-50 mm Hg). During the phenylephrine infusion, average heart rate decreased from 96 +/- 2.6 to 91 +/- 3.1 beats/min (NS), while mean normalized Vcf declined from 1.38 +/- 0.06 to 1.09 +/- 0.05 circ/sec (P less than 0.001) and normalized Vpw from 0.89 +/- 0.04 to 0.65 +/- 0.04 sec-1 (P less than 0.001). Nonnormalized velocities exhibited similar alterations (P less than 0.01). We conclude that in the normal human subject mean Vcf and mean Vpw are sensitive to acute alterations in heart rate and systemic arterial pressure. Thus, when ultrasound measures are used for serial assessment of left ventricular performance, the level of heart rate and systemic arterial pressure at which studies are obtained must be considered. Further, the sequential use of atropine and phenylephrine, as described in this study, provides an experimental model for the evaluation of the effects of drug treatment and other interventions on left ventricular performance in man.
Left ventricular aneurysm. Preoperative hemodynamics, chamber volume, and results of aneurysmectomy.
Authors: Watson L E , Dickhaus D W , Martin R H
Published: June 2012

Angiocardiographic characteristics of the residual contracting left ventricle (LV) have been examined in 16 patients with anterolateral ventricular aneurysms (VA). In each patient a contractile section (CS) of the LV was clearly demarcated from the remaining aneurysmal section (AS). Using a double hemispheroid model, volumes of CS and AS were separately estimated by a modified area-length method. The volume of CS plus AS agreed closely with the volume of total LV estimated by the conventional area-length method. End-diastolic volume (EDV) of total LV ranged from 79 to 312ml/72. Aneurysmal section volume ranged from 8 to 264 ml/m2. End-diastolic volume of the contractile section ranged from 52 to 159 ml/m2 (mean, 100+/-8 (se); normal, 78+/-6). Contractile section ejection fraction (EF) showed a wide range, from 15% to 79% (mean 40%+/-17% SD). Nine patients underwent resection of VA. Three of six operated patients with CS EF less than 44% died; no survivor in this group has improved by more than one functional class (New York Heart Association classification). Three operated patients had CS EF greater than 45%; all survived and are improved, two having moved from class IV to class I. These data suggest that the EF of the contracting residual LV may be an important predictor of the outcome of resection of VA.
Assessment of aortic insufficiency by transcutaneous Doppler ultrasound.
Authors: Boughner D R
Published: June 2012

Using a 2.2 MHZ directional Doppler ultrasound unit, the instantaneous peak aortic velocity pattern was recorded transcutaneously in 15 normal persons and 15 patients with aortic insufficiency. The transducer was positioned in the suprasternal notch and aimed posteriorly to cross the descending aortic arch at an angle approximately parallel to blood flow. The electrocardiogram, phonocardiogram, and carotid pulse tracings were recorded simultaneously. In patients with aortic insufficiency there was significant diastolic flow that was not present in normal persons. The planimetered area under the systolic and diastolic velocity tracings represents the distance forward and backward that the stroke volume moves. The ratio was used to approximate the percent regurgitation, which ranged from 9% to 68%. From left ventricular angiograms in the patients with aortic regurgitation single plane ventricular volume measurements were used to calculate ventricular output and when compared with the Fick cardiac output gave an estimate of true percent regurgitation. A strong correlation was obtained with the Doppler estimate (r=0.91), confirming that this simple ultrasound technique can accurately assess the degree of aortic insufficiency.
Ventricular quadrigeminy as a manifestation of concealed bigeminy.
Authors: Kerin N , Mori I , Levy M N
Published: June 2012

Long rhythm strips were analyzed from five patients with frequent ventricular extrasystoles. The predominant pattern was quadrigeminal; i.e., three sinus beats between extrasystoles. However, about 20% of the interectopic intervals contained numbers of sinus beats (S) greater than three. Analysis of the distribution of such values of S greater than 3 revealed that there were many more odd than even values (P less than 0.001). Also, carotid sinus pressure yielded only odd values of S greater than 3. This predominance of odd values strongly suggested the existence of concealed extrasystoles. Therefore, all odd values of S greater than 3 were analyzed to determine whether they satisfied the criterion for concealed bigeminy (S = 2n - 1) or for concealed quadrigeminy (S = 4n - 1). The distribution was found to satisfy the criterion for concealed bigeminy, suggesting that the quadrigeminal pattern was a manifestation of a 2:1 rather than a 4:1 block in a re-entry loop. Stable quadrigeminy occurs often in concealed bigeminy, because the re-entrant impulse finds the myocardium excitable after a normal R-R interval but refractory after a compensatory pause.
Nutrient myocardial blood flow in experimental myocardial ischemia. Effects of intraaortic balloon counterpulsation and coronary reperfusion.
Authors: Saini V K , Hood W B , Hechtman H B , Berger R L
Published: June 2012

This experimental study was designed to evaluate the effect of intraaortic balloon pumping (IABP) upon nutrient myocardial blood flow (NMBF) following acute myocardial ischemia in dogs, but also to determine whether IABP improves NMBF following revascularization. Localized myocardial ischemia was produced by ligation of one or two small branches of the circumflex coronary artery combined with a three hour snare occlusion of the left anterior descending coronary artery distal to the first septal branch. NMBF was measured by NaI131 washout at three points corresponding to the peripheral, intermediate, and central zones of the infarct. Occlusion of the coronary arteries reduced NMBF. Release of occlusion after three hours, or the equivalent of coronary artery revascularization, increased NMBF but did not restore it to control levels. The increase in flow was more marked in the peripheral zones of ischemia. IABP increased NMBF significantly both during and after release of occlusion. The effect was sustained after cessation of IABP only when the latter was maintained during the period of reperfusion. The results indicate that NMBF, defined by washout of a locally injected tracer, was improved by both IABP and reperfusion. The beneficial effect was maximal when the two techniques were combined.
Echocardiographic detection of mitral valve prolapse. Exclusion of false positive diagnosis and determination of inheritance.
Authors: Weiss A N , Mimbs J W , Ludbrook P A , Sobel B E
Published: June 2012

An important potential source of error in the echocardiographic diagnosis of mitral valve prolapse has been identified -- namely a systolic hammock-like pattern of the anterior and/or posterior mitral leaflet echoes, similar to that associated with true mitral valve prolapse, produced artifactually when the ultrasonic transducer is angulated inferiorly. Utilizing a modified, more specific technique we characterized the mode of inheritance and familial prevalence of this disorder. Among 74 subjects, composed of 57 first-degree relatives and 17 propositi with mitral valve prolapse, mitral valve prolapse was detected in 27 of 57 (47%) of the first-degree relatives. Fifty-three percent of female and 36% of male progeny of propositi were affected. Furthermore, familial transmission occurred from propositi to both sexes. Results of this study indicate that mitral valve prolapse is transmitted in an autosomal dominant mode with reduced male expressivity and a familial prevalence of 47% and that appropriate echocardiographic techniques must be employed to avoid a high incidence of false positive diagnosis.
Aortic stenosis surgery in infancy.
Authors: Keane J F , Bernhard W F , Nadas A S
Published: June 2012

During the past 14 years, 28 infants (23 males) underwent valvotomy for severe aortic stenosis at the Children's Hospital Medical Center in Boston. The median age was two months and the oldest patient was six months old. Congestive heart failure was present in all but two babies. Preoperatively, the electrocardiogram was abnormal in all, with left ventricular hypertrophy and a strain pattern being present in 19. At cardiac catheterization, the peak systolic ejection gradient (PSEG) ranged from 35-130 mm Hg (median 90 mm Hg). Associated cardiac lesions were present in 39%. Twenty-four infants underwent valvotomy with inflow occlusion. Four patients were operated upon using cardiopulmonary bypass. There were eight early and two late deaths. The 18 survivors have been followed from six months to 11 years (median five years). Only four are symptomatic. Mild aortic regurgitation developed postoperatively in six patients, moderate in one and severe enough to require valve replacement in another one. The electrocardiogram improved postoperatively in 15 patients, but became entirely normal only in one. Five children required a repeat valvotomy for residual stenosis 1-10 years after the original procedure (median four years). At this second operation, the majority of the valves were flexible and noncalcified, and valvotomy was accomplished without difficulty. One child who underwent valve replacement for aortic regurgitation at age two years is well seven years later.
Asymetric septal hypertrophy in childhood.
Authors: Maron B J , Henry W L , Clark C E , Redwood D R , Roberts W C , Epstein S E
Published: June 2012

Although considerable information is available concerning the clinical features and natural history of asymmetric septal hypertrophy (ASH) in adults, little is known of this disease in children. The clinical characteristics and course of 46 children with ASH, who were evaluated at the National Heart and Lung Institute, have been analyzed. Twenty-four children had obstruction to ventricular outflow; 22 children had no obstruction to ventricular outflow, including 11 patients without overt manifestations of cardiac disease other than echocardiographic evidence of ASH. Thirty-five of the 46 children have been followed for one to 16 years (average 7.4 years). These latter children represent that subgroup of patients with ASH referred to the National Heart and Lung Institute and diagnosed prior to the general availability of echocardiography. The clinical course of these patients was variable. Fourteen (40%) of the 35 patients improved or remained stable, including four patients who received propranolol. Ten (29%) of the 35 patients deteriorated clinically and 11 (31%) of the 35 patients died suddenly (4% mortality per year). Two of the patients who died suddenly had previously undergone operation (six and 13 years previously) with resultant abolition of the outflow gradient; four others were taking propranolol. Neither symptomatology, electrocardiographic abnormalities, heart size, left ventricular ejection or upstroke time, magnitude of outflow gradient, or left ventricular end-diastolic pressure proved predictive of sudden death. Excluding patients who had previous operation, eight (40%) of 20 patients with obstruction who were followed long term and one (9%) of 11 patients without outflow obstruction died suddenly. Thus, the clinical and hemodynamic spectrum of ASH in childhood is broad. However, deterioration in clinical condition or sudden death has been relatively common in children with overt signs of cardiac disease.
Electrocardiographic manifestations of concealed junctional ectopic impulses.
Authors: Fisch C , Zipes D P , McHenry P L
Published: June 2012

Thirteen episodes of concealed junctional ectopic impulses (JEI) in ten patients are described. In nine patients the JEI manifested as isolated automatic impulses and in one as a parasystolic junctional tachycardia. In addition to the previously described unexpected prolongation of the P-R, Type I and Type II A-V block, the following phenomena were recorded: 1) marked, greater than 400 msec, and persistent prolongation of the P-R interval, 2) striking changes in the duration of the P-R with an occasional sequence of R-P and P-r intervals simulating "supernormal" A-V conduction, 3) unexpected variation of the junctional escape interval explained by junctional parasystole with entrance block, 4) postponed compensatory pause, 5) concealed junctional discharge with reciprocation.
Cardiac imaging using a phased array ultrasound system. II. Clinical technique and application.
Authors: Kisslo J , vonRamm O T , Thurstone F L
Published: June 2012

A new two-dimensional ultrasound imaging system capable of producing high resolution tomographic images of the heart in real time has been developed. This system relies on phased array principles to rapidly steer the ultrasound beam through the structures under investigation. A hand-held linear array of 16 ultrasound transducers with overall dimensions of 14 mm at the site of contanct may be readily manipulated to image various cardiac structures. The resulting images are displayed in a circular sector format, 60 degrees in azimuth and typically 15 cm in range. At his maximum range, image frames consisting of 256 lines are generated at the rate of 20 frames/second. High azimuthal resolution throughout the field of view is assured by a focused transmit beam and by sweeping the focus of the receiver is synchrony with the range of returning echoes. Azimuthal resolution varies from 2 to 5 mm throughout the field of view while range resolution is 1.5 mm. This imaging system has proven particularly useful for the delineation of left ventricular spatial geometry by the identification of endocardium, myocardium, papillary muscles and interventricular septum. High quality images of anterior and posterior mitral leaflets, aortic root and aortic leaflets as well as left atrium and other cardiac structures have been obtained.
Echocardiography diagnosis of ruptured aneurysm of sinus of Valsalva. Report of two cases.
Authors: Matsumoto M , Matsuo H , Beppu S , Yoshioka Y , Kawashima Y , Nimure Y , Abe H
Published: June 2012

Echocardiographic features of two cases of ruptured congenital aneurysm of Valsalva sinus with (case1) and without (case 2) a supracristal ventricular defect were studied before and after surgery by standard echocardiography. M-mode scan and two-dimensional echocardiography. Discontinuity was observed in the echo from the aneurysm wall of the Valsalva sinus in case 1 with ruptured aneurysm, but was not observed in a similar case of unruptured aneurysm. Herniation of the right coronary cusp of the aortic valve into the right ventricular outflow tract was also observed in case 1. After surgical correction the echo from the aneurysm wall and from the herniated right coronary cusp of the aortic valve disappeared. Discontinuity in the echo from the anterior aortic wall and the interventricular septum also disappeared. In case 2, discontinuity in the echo from the anterior aortic wall, and tricuspid flutter with an abnormally low early diastolic peak were observed. These abnormalities disappeared after surgery. The ability of echocardiography to detect ruptured Valsalva aneurysm is discussed.
Anatomical configuration of the His bundle and bundle branches in the human heart.
Authors: Massing G K , James T N
Published: June 2012

The relationships among the His bundle, the origin of both bundle branches, and the interventricular (IV) septum were examined histologically in 32 human hearts, and the entire bundle branch systems were delineated in 13 of these. The His bundle in five hearts traversed the right IV septal crest, and the LBB origin was a very narrow stem (maximum 1.5 mm in cross-section) crossing from right to left through the inferior margin of the membranous septum. Proximal LBB anatomy was extremely variable, demonstrating multiple fiber groups which fanned out over the entire left septal surface. The LBB did not divide into two discrete divisions without multiple interconnections. The RBB formed an obtuse angle with the His bundle in 27 of 32 hearts. In those five hearts with "right-sided His bundles," the right bundle branch was a direct continuation. The clinical, electrophysiologic, and electrocardiographic implications of these anatomical observations are discussed.
Noninvasive stress testing. Methodology for elimination of the phonocardiogram.
Authors: Spodick D H , Lance V Q
Published: June 2012

Measurement by systolic time intervals (STI) of cardiac responses requires extremely careful recording during actual stress test performance. Previous work indicated no significant changes in the pulse transmission time (PTT) during exercise and other challenges. Since external STI depend on the carotid pulse offset by the PTT as an aortic curve equivalent, stable PTT implies that timing of the carotid upstroke (CARu) and the carotid incisura (CARIN) would respectively track the pre-ejection period (i.e., the externally calculated onset of the aortic upstroke) and the aortic incisura which is externally timed by the aortic component of SII (IIA). In ten subjects, STIs were recorded at supine rest, sitting, standing, during prompt and sustained squatting and during isometric and dynamic exercise. The results demonstrated the tracking of both points: regression slopes and correlation coefficients were close to 1.00 for each series and for each subset. Coefficients of correlation (r) and of determination (r2) were uniformly high for all challenges except isometric handgrip (IHG). Since left ventricular ejection time is obtained directly from the pulse curve, with the exception of IHG, STI responses during stress testing can be measured without a phonocardiogram.
Q fever endocarditis in Queensland.
Authors: Wilson H G , Neilson G H , Galea E G , Stafford G , O'Brien M F
Published: June 2012

Thirteen patients with proven Q fever endocarditis and three additional patients with probable endocarditis are reviewed. The most helpful diagnostic test is the demonstration of a high complement fixing antibody titre to Phase 1 antigen of Coxiella burneti. The macroscopic pathology of the aortic valve is described and includes aneurysmal pockets in the aortic wall and valve annulus which are demonstrable angiographically. Evidence is presented that the infection may be controlled by prolonged tetracycline therapy and that this is accompanied by a falling antibody titre to Phase 1 antigen. Valve replacement is undertaken only for symptomatic and hemodynamic indications. The combined tetracycline therapy and valve replacement have produced a fall in titres with eradication of infection and palliation of the cardiac disability in all patients followed for long periods.
Effects of isometric exercise on the end-diastolic pressure, volumes, and function of the left ventricle in man.
Authors: Flessas A P , Connelly G P , Handa S , Tilney C R , Kloster C K , Rimmer R H , Keefe J F , Klein M D , Ryan T J
Published: June 2012

Changes induced in left ventricular (LV) hemodynamics by isometric exercise were analyzed in 43 patients: 30 with coronary heart disease (CAD), four with noncoronary heart disease, nine normal. Volumes were angiographically determined and correlated with left ventricular end-diastolic pressure (LVEDP) both at rest and during the fifth minute of 30% sustained handgrip (HNG). All normals and eight with CAD improved LV function during HNG. LVEDP decreased or remained constant, end-diastolic volume (EDV) decreased, end-systolic volume (ESV) decreased, as ejection fraction (EF) remained constant. None of these eight CAD cases altered their regional LV contraction pattern during HNG. Twenty-five patients, 21 CAD and four nonCAD, showed diminished LV function during HNG. LVEDP increased, EDV decreased, ESV increased, as EF declined. In these 21 CAD patients, at least one major coronary vessel was narrowed 70% or more and, with but two exceptions, was not supported by adequate collaterals. In 18, new asynergic zones developed in previously normally contracting areas or pre-existing asynergic zones extended during HNG.