bluuebunny/crossref_metadata_2025 huggingface dataset:
Echographic assessment of atrial transport, mitral movement, and ventricular performance following electroversion of supraventricular arrhythmias.
Authors: DeMaria A N , Lies J E , King J F , Miller R R , Amsterdam E A , Mason D T
Published: June 2012

Controversy attends the extent and temporal sequence of improvements in hemodynamic function resulting from the return of atrial contraction following cardioversion of supraventricular arrhythmias. Thus, mitral, left atrial (LA) and left ventricular (LV) echograms were obtained before and one hour after conversion of supraventricular arrhythmias to normal sinus rhythm by direct current countershock in patients with chronic coronary disease or cardiomyopathies without valvular dysfunction. The duration of the rhythm disturbance varied from one day to five years in 22 patients and was indeterminate in 13. Atrial systole immediately produced prominent mitral "A" waves with anterior valve excursion of 7.5 mm (range 3 to 12) in 33 of the 35 patients (94%). The two patients with atrial electromechanical dissociation reverted to atrial fibrillation within one week. Cardioversion caused a decline in LA diameter (3.5 to 3.2 cm, P less than .001) and a rise in LV end-diastolic dimension (5.2 to 5.5 cm, P less than .001) while LV end-systolic dimension was unchanged (4.2 cm). Thereby stroke volume rose. Heart rate fell an average of 16 beats/min. Depressed cardiac output was improved + 0.84 L/min/m-2. Thus, in the majority of patients with acute or chronic supraventricular arrhythmias without mitral valve disease, cardioversion promptly restores effective atrial contraction, decreases LA size, and results in substantial hemodynamic benefit.
Measurement of right and left ventricular systolic time intervals by echocardiography.
Authors: Hirschfeld S , Meyer R , Schwartz D C , Korfhagen J , Kaplan S
Published: June 2012

One of the noninvasive methods of evaluating left ventricular performance is the measurement of left ventricular systolic time intervals (LVSTI). However, noninvasive measurement of right ventricular systole by this technique has been unreliable because of the inability to accurately time the onset of right ventricular ejection. Excellent correlation of LVSTI measured from the carotid pulse and those determined from the echocardiogram was demonstrated in 15 patients. STI of the right ventricle (RVSTI) were measured in a similar fashion from the pulmonary valve echo in 11 normal children. Right ventricular ejection time (RVET) was longer than left ventricular injection time (LVET). Right ventricular pre-ejection period and RPEP was shorter than left ventricular pre-ejection period (LPEP). In 15 children with transposition of the great arteries (TGA) the situation was reversed. RVET was shortened and RPEP was prolonged as the right ventricle contracted against systemic resistance; whereas, the LVET lengthened and LPEP shortened with ejection into a low pressure pulmonary circuit. Our studies in a total of 41 patients indicate the accurate, noninvasive measurement of right, as well as left, ventricular STI can be obtained with the use of echocardiography.
A comparison of systolic time intervals derived from the central aortic pressure and from the external carotid pulse tracing.
Authors: Van de Werf F , Piessens J , Kesteloot H , De Geest H
Published: June 2012

In 26 patients a direct comparison was made of systolic time intervals derived from the right and left external carotid pulse tracing and from the central aortic pressure, simultaneously recorded by means of a catheter-tip micromanometer. In addition, the delay time (required for pulse wave transmission to the neck) of the upstroke (DUEC) and incisura (DIEC) of the external carotid pulse tracing was studied. The influence of changes in heart rate on these intervals was evaluated by right atrial pacing. At resting frequencies DUEC exceeded DIEC by 4 to 4.5 msec (P less than 0.005). Increasing heart rate did not influence DUEC but prolonged DIEC. Differences between DUEC and DIEC were associated with a decrease and reversal with increasing heart rate (tau = 0.52, on the right carotid pulse; tau = 0.65, on the left pulse). Internally and externally measured left ventricular ejection time and pre-jection period were strongly correleated. Significant differences in absolute values were also observed. Whether these differences were positive or negative was dependent on heart rate. At rest external left ventricular ejection time was 4 to 4.5 msec (P less than 0.005) shorter, external pre-ejection period 5.5 to 6 msec (P less than 0.005) longer than corresponding intervals measured internally. At heart rates above plus or minus 100 beats/min the relationships were reversed. No significant differences could be demonstrated between these intervals measured on the right and left external carotid pulse.
Dynamic determinants of letf ventricular diastolic pressure-volume relations in man.
Authors: Gaasch W H , Cole J S , Quinones M A , Alexander J K
Published: June 2012

Left ventricular (LV) diastolic pressure (P), volume (V), and rate of change of volume (dV/dt) were determined at 16.7 msec intervals in 17 patients (simultaneous micromanometer and single plane volume angiography). Four patients had mitral stenosis with atrial fibrillation and 13 patients (three normal, two congestive cardiomyophathy, three LV hypertrophy, and five coronary artery disease) were in normal sinus rhythm. Maximum early diastolic filling rates (max dV/dt) in the normal and cardiomyopathy patients were similar and ranged from 269 to 370 cc/m-2/sec; in coronary artery disease and LV hypertrophy, max dV/dt ranged from 197 to 290 cc/m-2/sec and 213 to 255 cc/m-2/sec respectively; in mitral stenosis, max dV/dt ranged from 215 to 270 cc/m-2 sec. The peak filling rate during atrial systole ranged form 60 to 240 cc/m-2/sec in the 13 patients with sinus rhythm. The instantaneous diastolic P-V data were fit by an exponential equation (P = be-kV) and the P-V relation throughout diastole was represented by the best fit line. The rate constant (k) in the equation was highest in the patient with IHSS and lowest in those with large dilated hearts. In mitral stenosis with atrial fibrillation the fit of the equation to the P-V data appeared better than in the patients with normal sinus rhythm. Peak ventricular filling rate during atrial systole varied directly with LV volume distensibility at the onset of atrial systole (r = 0.64). Data suggest that dynamic mechanical properties of the LV influence the diastolic P-V relations and that pressure "deviations" (deltaP) from the best fit line during atrial systole may be related to viscous drag. In a given ventricle the velocity dependence of deltaP appears to be modified by the volume distensibility of the ventricle. Variable rates of filling may preclude the assumption of an exponential relation between P and V throughout diastole and therefore may limit estimates of diastolic distensibility or compliance which rely on such an assumption.
Clinical use of sodium nitroprusside in chronic ischemic heart disease. Effects on peripheral vascular resistance and venous tone and on ventricular volume, pump and mechanical performance.
Authors: Miller R R , Vismara L A , Zelis R , Amsterdam E A , Mason D T
Published: June 2012

Although hemodynamic benefit has been shown with sodium nitroprusside (NP) in acute coronary pump failure, complete understanding of the mechanisms of action of the agent on the cardiocirculation and its value in chronic ventricular dysfunction are lacking. This investigation evaluates the effects of NP on the systemic and regional arterial and venous beds and on cardiac dynamics, ventricular volumes, contractile state and myocardial energetics in long-standing congestive heart failure. Twelve patients with chronic coronary pump dysfunction received NP infusion to lower systolic pressure to 95-105 mm Hg. Left ventricular (LV) function was assessed directly by angiographic volumes and high fidelity pressure, and peripheral circulatory dynamics were determined simultaneously by forearm arterial and venous plethysmography. NP reduced mean arterial pressure (MAP) from 88.2 to 73.4 mm Hg (P less than 0.05) and significantly (P less than 0.05) enhanced the variables of LV performance: LV end-diastolic pressure (EDP) diminished from 18.5 to 9.9 mm Hg; ejection fraction rose from 0.47 to 0.55; percent of LV segmental shortening increased; and isovolumic and ejection indices of contractility improved. Concomitantly, NP reduced the indices of myocardial oxygen demands of ventricular tension time index and LVED volume index. These salutary effects on LV performance and energetics occurred secondary to peripheral arterial and venous dilation (P less than 0.05) produced by NP: total systemic vascular resistance was lowered from 1590 to 1310 dynes sec cm--5; forearm vascular resistance diminished from 46 to 37 mm Hg/ml/100 gm/min; and forearm venous tone fell from 14.2 to 10.1 mm Hg/cc. Depressed stroke index (SI) and cardiac index (CI) increased (P less than 0.05) with NP: despite the fall in LVEDP, when ventricular filling pressures with the agent were at levels slightly above normal. Dextran infusion given with NP to restore LVEDP to moderately elevated values increased SI and CI (P less than 0.05) when NP alone produced no change in stroke output. Thus, the peripheral vasodilator properties of nitroprusside improve LV function by reducing impedance to ventricular ejection, while MVO2 is diminished by decreasing LV preload and afterload through relaxing actions
Transfemoral plug closure of patent ductus arteriosus. Experiences in 61 consecutive cases treated without thoracotomy.
Authors: Sato K , Fujino M , Kozuka T , Naito Y , Kitamura S , Nakano S , Ohyama C , Kawashima Y
Published: June 2012

We successfully closed the isolated patent ductus arteriosus in 58 of 61 consecutive patients using the transfemoral-catheter method originally introduced by Porstmann in 1968. To perform this technique more safely and reliably, some instrumental and technical improvements were made. The indications for this method have been expanded to include the cylindrical or window-type ductus as well as the conical-shaped ductus. Classification into three groups of the configuration of the ductus by angiography has been useful in selecting the shape of the closing plug. Whenever feasible, we consider the catheter technique to be the method of choice to close the ductus.
Predictive implications of stress testing. Follow-up of 2700 subjects after maximum treadmill stress testing.
Authors: Ellestad M H , Wan M K
Published: June 2012

Follow-up data on 2700 subjects who had had maximum stress tests were assembled in life tables. A positive test, characterized by ST-segment depression of 1.5 mm, 0.08 sec from the J point, predicted an incidence of some new coronary event of 9.5% a year, as compared with 1.7% in those with a negative test. The incidence of infarction and death was also significantly higher than in the negative responders. Early onset of ischemia occurring at moderate exercise (4 metabolic equivalents-METS) resulted in an incidence of all coronary events of 15% a year, while ischemia first manifested at the seventh minute of exercise (approximately 8 METS) results in an incidence of only 4% per year. The magnitude of ST depression and the age of onset of ischemia failed to influence the incidence of coronary events. A myocardial infarction previous to the test increased the incidence of events in both positive and negative responders. The positives with a previous infarction had more than double the incidence of coronary events than the positive responders with no pre-existing infarction. Those with chronotropic incompetence had a high incidence of coronary events even though the ECG response to exercise was normal.
Relation between contractile reserve and prognosis in patients with coronary artery disease and a depressed ejection fraction.
Authors: Cohn P F , Gorlin R , Herman M V , Sonnenblick E H , Horn H R , Cohn L H , Collins J J
Published: June 2012

Postextrasystolic potentiation (PESP) and 1-epinephrine infusion have previously been shown by the ventriculographic technique to augment left ventricular wall motion in patients with coronary artery disease. The present study relates the magnitude of this augmentation to short-term prognosis in 56 patients with coronary artery disease and a factor already identified with reduced life expectancy, i.e., an abnormal ejection fraction (EF less than .50). Forty-two patients received PESP and 14 1-epinephrine infusion. Based on severity of symptoms and technical suitability, 37 were treated surgically and 19 medically. Mean follwo-up times were 11.7 and 14.3 months, respectively. The mean increase in EF induced by PESP or 1-epinephrine infusion was significantly greater in patients who subsequently had good results from either surgical or medical therapy than in those who died or had progressive cardiac deterioration. In addition, those patients with an increase in EF of .10 or greater had a statistically greater chance of doing well than patients with less augmentation. Evaluation of change in ejection fraction after inotropic stimulation in patients with depressed ejection fractions is helpful in identifying those patients with greatest contractile reserve and hence better short-term prognosis with eigher medical or surgical therapy. Because of its ease of performance and greater enhancement of contractility, PESP is preferred to 1-epinephrine infusion as the inotropic stimulus of choice.
Hemodynamic effects of nitroglycerin in acute myocardial infarction.
Authors: Williams D O , Amsterdam E A , Mason D T
Published: June 2012

Nitroglycerin (NTG) has recently been suggested to decrease myocardial ischemia and enhance cardiac pump function during acute myocardial infarction (AMI). To evaluate the sublingual agnet in this condition, the hemodynamic effects of 0.4 mg NTG administered to 16 supine patients during the first 72 hours of AMI were determined serially 5, 10 to 15, and 20 to 30 minutes post-NTG. Data were evaluated for the entire group, as well as for six patients with normal pulmonary artery wedge pressure (PAW) (less than or equal to 12 mm Hg; mean 7) who formed group I and for ten patients with elevated PAW (greater than 12 MM Hg; mean 19) who comprised group II. In the 16 patients, NTG resulted in significant decreases in PAW (14 TO 7 MM Hg; P less than .01), mean systemic arterial pressure (MAP) (95 TO 82 MM Hg; P less than .01), cardiac index (CI) (1.79 TO 1.46 L/min/m-2; P less than .02), stroke index (SI) (24 TO 18 CC/M-2; P less than .01) and stroke work index (SWI) (27 TO 20 GM TIMES M/M-2; P less than .01). These alterations were significant in both subgroups, with the decline in PAW greater (P less than .05), while there was no change in group II. There was no significant change in total peripheral vascular resistance (TPVR) for the entire group or in the two subgroups. This study demonstrates that, regardless of initial left ventricular filling pressure, sublingual NTG given in the acute phase of AMI results in rapid fall in PAW, concomitant with decreases in systemic blood pressure, cardiac output and SWI, without changes in TPVR and with little or no effect on heart rate. Since TPVR was unaltered, the decline in MAP was due to fall in cardiac output. Thus, the principal action of sublingual NTG in AMI appears to be systemic venodilation with consequent reduction of ventricular preload. This effect is translated into decline ofpump output even in patients with high initial filling pressures. Although NTG may rapidly relieve pulmonary congestion and lower myocardial oxygen consumption, use of the agent sublingually is limited in AMI because these salutary effects are accomppanied by potentially deleterious fall in cardiac output and systemic blood pressure.
Response of the left ventricle in coronary artery disease to postextrasystolic potentiation.
Authors: Hamby R I , Aintablian A , Wisoff G , Hartstein M L
Published: June 2012

Left ventricular volumes and contractile patterns were evaluated during the first sinus beat after a compensatory pause resulting from ventricular arrhythmia and were compared to the second sinus beat (control beat) in order to evaluate the effect of postextrasystolic potentiation. Twelve patients had no evidence of heart disease (group I). Fifty patients had coronary artery disease and included 14 patients (group IIa) with no prior myocardial infarction and a normal left ventricular contractile pattern and 19 pateints (group IIb) with an abnormal contractile pattern. Seventeen pateints (group IIc) had a documented transmural myocardial infarction as well as an abnormal left ventricular contractile pattern. In all patients the first postextrasystolic sinus beat, when compared to the second sinus beat, demonstrated increases in stroke volume and ejection fraction and decrease in end-systolic volume. There were no qualitative changes in the contractile pattern in the immediate postextrasystolic beat in the patients with normal left ventricular function. In both group IIb and group IIc the changes in end-systolic volume, stroke volume and ejection fraction were significantly greater than observed in groups I and IIa. Abnormal wall segments present in the control beat in groups IIb and IIc demonstrated after postextrasystolic potentiation a normal contractile pattern, improved pattern or no change when compared to the control beat. Abnormal wall segments were more likely to revert to normal as a result of postextrasystolic potentiation in group IIb than group IIc. Akinesia was less likely to revert completely to normal than hyposinesia. In 20 of 24 patients the changes in contractile pattern after aortocoronary bypass surgery corresponded to those observed as a result of postextrasystolic potentiation.
The effect of intracoronary injection of contrast medium upon coronary blood flow.
Authors: Bassan M , Ganz W , Marcus H S , Swan H J
Published: June 2012

The changes in coronary blood flow in response to intracoronary injection of 3 ml of 76% Renografin were studied in 47 patients using the thermodilution technique for continuous measurement of coronary sinus blood flow. Within seconds after left coronary injection, an increase in coronary sinus flow began which peaked at an average of 53% above control in 5-10 seconds. There was a corresponding decrease in coronary resistance. Flow returned to control level in almost all patients within one minute of injection. Twenty-four of 35 patients had no change in coronary sinus flow in response to right coronary injection. This can be explained by the fact that most of the venous flow from the right coronary artery returns in such a way that it cannot be measured by the coronary sinus catheter. Of the eleven patients who did show an increase, seven had angiographically documented right to left collaterals, suggesting that the increase in flow was the result of vasodilatation of the left coronary bed by contrast arriving via the right to left collaterals. The percent changes in flow and resistance in response to left coronary injection were isgnificantly greater in the 13 normals than in the 34 with obstructive disease of the left coronary artery (P lessthan 0.01). Flow rose 70 plus or minus 27% (mean plus or minus standard deviation) in the normals versus 46 plus or minus 25% in the patients with coronary artery disease, while resistance fell 44 plus or minus 9% versus 33 plus or minus 11%. The differences, however, were not sufficient for these changes to be of value in the assessment of the degree of impairment of the coronary arterial bed in the individual patient.
A clinical and follow-up study of right and left bundle branch block.
Authors: Rotman M , Triebwasser J H
Published: June 2012

The experience with bundle branch block at the USAF School of Aerospace Medicine was reviewed. The clinical and follow-up status was evaluated in 394 subjects with right bundle branch block (RBBB) and 125 subjects with left bundle branch block (LBBB). The majority of subjects were asymptomatic at the time of bundle branch block diagnosis. The subjects were divided into subfroups based on electrocardiographic (EEG) findings to determine if any one subfroup was at higher risk for initial or follow-up morbidity of cardiobascular disease or follow-up mortality. At initial diagnosis and clinical evaluation, 94% of RBBB and 89% of LBBB subjects had no evidence of cardiobascular disease. In the RBBB group, 3 and 2% had cornary heart disease and hypertension, respectively; in LBBB subjects, 9 and 7% had cornary heart disease and hypertension, respectively. No one ECG subfroup in either the RBBB or LBBB group had a higher incidence of cardiobascular disease. Complete follow-up information was available in 94% of the RBBB subgroup subjects and 91% of the LBBB group. In the follow-up period, new cases of coronary heart disease and hypertension occurred in 6% of the RBBB group and 5 and 8%, respectively, in the LBBB group. Fourteen (4%) RBBB and nine (8%) LBBB subjects died during the follow-up period. No differences for follow-up groups. Progressive electrical dysfunction in the form of complete heart block occurred in one subject each absence, and degree of associated cardiobascular disease. Furthermore, within the age limits of the present aeromedical implications of bundle block are discussed.
Comparison of cardiac refractory periods in children and adults.
Authors: DuBrow W , Fisher E A , Amaty-Leon G , Denes P , Wu D , Rosen K , Hastreiter A R
Published: June 2012

Atrial (A) and A-V nodal (AVN) effective and functional refractory periods (ERP & FRP) were determined by atrial extrastimulus technique in 40 children, aged 7 months to 16 years, with normal P-R intervals and QRS durations. These data were compared to adult data at longest cycle lengths (CL) assuring atrial capture. All values are listed in msec as means plus or minus standard errors of the means. CL was 566 plus or minus 15 in children and 699 plus or minus 29 in adults (P less than .001). Refractory periods (RP) in children and adults were, respectively: AERP 196 plus or minus 9 and 239 plus or minus 13 (P less than .01), AFRP 225 plus or minus 8 and 284 plus or minus 11 (P less than .001), AVNERP 239 plus or minus 11 and 293 plus or minus 7 (P smaller than .001), AVNFRP 360 plus or minus 13 and 403 plus or minus 7 (P smaller than .005). RP were then compared at three equivalent CL ranges: CL1, 850-600; CL2 599-460; CL3 459-280. The following RP were significantly shorter in children (P smaller than .05-.001): AERP, AFRP, AVENERP and AVNFRP at CL2 and CL3. RP of the bundle branches were compared and tended to be shorter in children. In conclusion, atrial and A-V nodal ERP and FRP are shorter in children than adults. This shortening is only partially related to the shorter CL in children. These data are germane to understanding the maturation of the conduction system in man.
Multiform ventricular ectopic rhythm. Evidence for multiple parasystolic activity.
Authors: El-Sherif N , Samet P
Published: June 2012

Six patients whose standare electrocardiograms showed multiform ventricular ectopic rhythm were studied. All patients had advanced organic heart disease and a significant intraventricular conduction defect (left bundle branch block in five and right bundle branch block plus left anterior hemiblock in one). The ventricular arrhythmia was generally resistant to antiarrhythmic therapy. Five of the six patients died after 2 to 6 months form the period of observation from terminal heart failure. None died suddenly. The ventricular arrhythmia did not seem to be directly related to mortality in any patient. Critical analysis of several long rhythm strips in each case revealed that discharge from multiple ventricular parasytolic foci shared in the multiform ventricular activity. The concurrent discharge of a minimum of three parasytolic foci and a maximum of six foci was found in the same case with a total of 24 parasystolic foci in the six patients. There was a remarkable constancy of the QRS configuration of all parasytolic foci over periods of observation of up to 16 months. However, 22 out of 24 parasystolic rhythms showed significant variation in the apparent rhythm or the administration of drugs. Fourteen parasytolic foci showed evidence of exit block, some of which were exaples of a rapid parasystole with a high degree of exit block. The study suggests that multiform ventricular ectopic rhythm may, in part, be due to the concurrent discharge of multiple parasystolic foci.
Simultaneous echocardiographic phonocardiographic recordings at rest and during amyl nitrite administration in patients with mitral valve prolapse.
Authors: Winkle R A , Goodman D J , Popp R L
Published: June 2012

Simultaneous electrocardiograms, phonocardiograms, and echocardiograms were recorded in 21 patients with mitral valve prolapse. Four patients with holosystolic mitral valve prolapse on echocardiogram had smaller resting end-diastolic volumes than the remaining 17 patients with late systolic echocardiopraphy prolapse (p greater than 0.01). Thirteen of the 17 patients with late systolic prolapse had phonocardiograhically recorded auscultatory phenomena. The initial vibrations of the auscultatory phenomena occurred after the onset of echocardiographic prolapse, but prior to maximal echocardiographic mitral valve prolapse. Amyl nitrite was administered to all patients. Three of the 17 patients with late systolic prolapse developed holosystolic prolapse, while the remaining 14 retained the late systolic prolapse pattern during amyl nitrite inhalation. In these 14 patients, the onset of mitral prolapse occurred earlier in systole due to decrease in the duration of systole prior to onset of mitral valve prolapse (p greater than 0.001). This corresponded with the occurrence of auscultatory phenomena earlier in systole. Twelve patients had left ventricular volumes recorded during amyl nitrite inhalation and all showed a decrease in left ventricular volumes (greater than) 0.001). These findings confirm the temporal relationship of mitral valve prolapse and onset of auscultatory phenomena in these patients. It suggests that the movement of auscultatory phenomena earlier in systole during amyl nitrite inhalation is related to earlier prolapse of the mitral valve, and that a decrease in ventricular valume is a tenable explanation for the earlier onset of prolapse.
Acute effects of low doses of alcohol on left ventricular function by echocardiography.
Authors: Delgado C E , Gortuin N J , Ross R S
Published: June 2012

The ultrasound method for measuring the dimensions of the left ventricle was utilized to study the effect of oral doses of alcohol on left ventricular function in normal volunteers. Systolic time intervals were also measured. Seven subjects received 0.7 g/kg of ethanol (group I) and six subjects recieved 1.15 g/kg (group II). The peak of blood alcohol levels in the two groups were 75 mg/100 ml and 138 mg/100 ml respectively. There was a 6% decrease in the fractional change in the minor axis of the left ventricle in group I patients which resulted in a decrease in ejection fraction (p greater than 0.05). In group II patients, there was a 3% decrease in the fractional change in the minor axis of the left ventricle, but the change of ejection fraction was not significant. Since there was no significant difference between the physiological effects observed in groups I and II, the two groups were combined. In the combined group, at 30 minutes after the ingestion of alchol, the heart rate was increased by 11%, the fractional change in the minor axis of the left ventricle decreased by 6%, the ejection fraction decreased by 4% (p greater than 0.01) and Vcf decreased by 5%. These data suggest that in normal subjects myocardial contractility is depressed following the ingestion of alcohol.
On the clinical value of calibrated displacement apexcardiography.
Authors: Denef B , Popeye R , Geest H D , Kesteloot H
Published: June 2012

A new type of displacement transducer for recording the calibrated left apexcardiogram (QLAC) has been evaluated in 69 normal subjects and 99 cardiac patients. Total displacement of QLAC (TD), its peak first derviative (peak dD/dt (t-peak dD/dt). A strong corretation exists between peak dD/dt and TD in normal subjects (r=0.95) and the deviation from the normal relationship allows a separation between normal and abnormal ventricular function. In normal subjects (dD/dt/Dt) max averaged 34.2 plus or minus 5.7 sec-1; it was signigicantly lower in patients with congestive cardiomyopathy (26.5 plus or minus 6.3 sec-1 p greater than 0.005). This index correlates with left ventricular end-diastolic pressure (LVEDP) (R = - 0.69) and with ejection fraction (R - 0.66) and behaves as expected during positive and NEGATIVE INOTROPIC interventions. The index (dD/dt/Dt) max is superior to TD and peak dD/dt, being less variable independent of thorax circumference and better correlated with hemodynamic parameters. The index t-peak dD/dt was 53.9 plus or minus 9.5 msec in normal subjects and 81.6 plus or minus 18.9 msec in patients with congestive cardiomyopathy (p greater than 0.001). This time-interval correlates weakly with LVEDP (R = 0.04) and with ejection fraction (R = - 0.66). It is concluded that the normalized first derivative of QLAC provides useful information on left ventricular function.
Anomalous left coronary artery from pulmonary artery. An eight year angiographic follow-up after saphenous vein bypass graft.
Authors: Chaitman B R , Bourassa M G , Lespérance J , Grondin P
Published: June 2012

We have presented a 7-week and 8-year postoperative angiographic follow-up of a 36-year-old man who had an anomalous left coronary artery arising from the pulmonary artery and who had an aortocornary bypass graft to the left anterior descending artery. The late study showed 1) a large, well functioning patent graft, 2) lack of significant postoperative change in the size of the right coronary artery and 3) new collateral vessels between the distal left anterior descending and left circumflex coronary arteries and persistence of collateral vessels between the distal right and left circulflex coronary arteries. This report is the longest known angiographic follow-up of a patient with this anomaly who has been treated with bypass surgery.
Premature pulmonic valve opening following sinus of Valsalva aneurysm rupture into the right atrium.
Authors: Weyman A E , Dillon J C , Feigenbaum H , Chang S
Published: June 2012

Echocardiographic features of a patient with sinus of Valsalva aneurysm rupture into the right atrium are described. The aneurysm presented as a dense echo-producing mass in the right atrium which descended into the tricuspid orifice during diastole and withdrew back into the atrium during ventricular systole. Pulmonic valve exho motion demonstrated early diastolic pulmonic valve opening indicating an early right ventricular diastolic pressure rise exceeding simultaneous pulmonary artery pressure. Since the aorta is the only source of early diastolic pressure in excess of pulmonary artery pressure available to the right heart, this finding of early diastolic pulmonic valve opening indicated the presence of a fistula between the aorta and right heart. Other interesting echocardiographic features of this case are also presented.
Echocardiographic recognition of the mitral valve-posterior aortic wall relationship.
Authors: Strunk B L , Guss S B , Hicks R E , Kotler M N
Published: June 2012

Aortic-mitral valve discontinuity has previously been described in double outlet right ventricle, endocardial cushion defect, single ventricle, tetralogy of Fallot, and prolapse of the mitral valve. We are reporting two additional examples of aortic-mitral valve discontinuity including 15 cases of gross left ventricular dilation and a case of acute pneumococcal bacterial endocarditis with a large subannular erosion. While nonspecific, aortic-mitral valve discontinuity is a clinically important sign that should be sought with slow-M-mode scanning and strip chart recording.
Circulatory and metabolic effects of glycerol infusion in patients with recent cerebral infarction.
Authors: Meyer J S , Itoh Y , Okamoto S , Welch K M , Mathew N T , Ott E O , Sakaki S , Miyakawa Y , Chabi E , Ericsson A D
Published: June 2012

The effect of intravenous infusion of 10 per cent glycerol on regional cerebral blood flow (using hydrogen bolus and Xenon-133 (133Xe) clearance methods) and metabolism was investigated in 57 patients with recent cerebral infarction. Hemispheric blood flow (HBF) increased, together with increase in regional cerebral blood flow (rCBF) and cerebral blood volume (rCBV), in foci of brain ischemia. Hemispheric oxygen consumption (HMIO2) decreased together with hemispheric respiratory quotient. Systemic blood levels of glucose, lactate, pyruvate, and triglycerides also increased after glycerol while free fatty acids (FFA) and inorganic phosphate (Pi) decreased. Hemispheric glucose consumption was unaltered after glycerol so that hemispheric glucose to oxygen ratio tended to rise. Pyruvate and lactate production by brain was unchanged. Glycerol moved across the blood brain barrier into brain and cerebrospinal fluid (CSF). Release of FFA and Pi from infarcted brain was reversed by glycerol. Total phosphate balance was maintained actoss brain both before and after glycerol infusion. Triglycerides increased in CSF after glycerol, originating either from cerebral blood or as a result of lipogenesis in cerebral tissue. The EEG Recording and neurological status of the patients improved despite decreased brain oxygen consumption. Results of this study suggest that after intravenous infusion of 10 per cent glycerol in patients with recent cerebral infarction, glycerol rapidly enters the CSF and brain compartments and favorably affects the stroke process in two ways: first, by redistribution of cerebral blood flow with increase in rCBF and rCBV in ischemic brain secondary to reduction in focal cerebral edema; and second glycerol may become an alternative source of energy either by being directly metabolized by the brain, or indirectly, by enhancing lipogenesis, or by both processes. Involvement of glycerol in lipogenesis with esterification to accumulated FFA might lead to improved coupling of oxidative phosphorylation, a hypothesis that fits the finding of improved neuronal function despite further decrease in cerebral hemispheric oxygen consumption.
The course of the conduction system in single ventricle with inverted (L-) loop and inverted (L-) transposition.
Authors: Bharati S , Lev M
Published: June 2012

The conduction systems of three hearts with single ventricle and inverted (L-) loop and inverted (L-) transposition were studied by serial section. The course of the conduction system was similar in all three hearts. The regular (posterior) atrioventricular (A-V) node was rudimentary and did not form the bundle of His. An accessory (anterior) A-V node was present in the roof of the right atrium. This node pierced the connective tissue adjacent to the right side of the pulmonary annulus to form the bundle of His. The bundle proceeded into the main ventricular chamber lying on the septum between this chamber and the small outlet chamber. It bifurcated a varying distance from the defect in this septum. The right bundle branch proceeded through the septal wall to the trabeculae of the outlet chamber. The left bundle branch proceeded to caudad on the anterior wall of the main ventricular chamber. An unusual feature in one case was the splitting of the anterior node into two parts, one forming the bundle of His, and the other giving off Mahaim fibers to the ventricular myocardium. The surgical importance of avoiding the right side of the pulmonary annulus and the region adjoining the defect is stressed.
Intraventricular conduction in man studied with an endocardial electrode catheter mapping technique. Patients with normal QRS and right bundle branch block.
Authors: Kastor J A , Goldreyer B N , Moore E N , Shelburne J C , Manchester J H
Published: June 2012

The sequence of intraventricular conduction has been studied in a total of 60 patients, 38 of whom had normal QRS morphology and 37 of whom had right bundle branch block (RBBB) either present continuously or produced as functional aberrant RBBB by the introduction of atrial premature depolarizations or by rapid atrial pacing. Activation times were measured by intracardiac electrode catheters positioned at the right ventricular inflow tract (RVIT), right ventricular apex (RVA), right ventricular outflow tract (RVOT), left ventricular apex (LVA) and left ventricular outflow tract (LVOT). The activation after beginning of QRS in milliseconds plus or minus 1 SD and the number of patients studied at each location were: RVIT--normal 23 plus or minus 13 (15 patients); RVIT-RBBB 49 plus or minus 16 (15 patients); RVA--normal 18 plus or minus 9 (28 patients); RVA-RBBB 54 plus or minus 16 (30 patients); RVOT--normal 40 plus or minus 10 (28 patients); RVOT-RBBB 78 plus or minus 21 (30 patients);LVA--normal 9 plus or minus 9 (18 patients); LVA-RBBB 6 plus or minus 10 (10 patients); LVOT--normal 45 plus or minus 13 (10 patients); LVOT-RBBB 32 plus or minus 9 (7 patients). Significant differences observed were: RVA-normal versus RVA-RBBB P smaller than 0.001; RVOT-RBBB P smaller than 0.001; RVA-normal versus LVA-normal P smaller than 0.005; LVA-normal versus LVA-RBBB NS, LVOT-normal versus LVOT-RBBB P smaller than 0.05. The LVOT change was unexpected and suggests changes in left ventricular depolarization may occur when right bundle branch block develops. In patients with RBBB the activation of the RVA (r equals 0.82) and of the RVOT (r equals 0.68) was directly related to the duration of QRS. Changes in activation time when RBBB was induced by rapid atrial pacing or by introduction of atrial premature depolarizations were: RVA (7 patients) 19 plus or minus 11 to 56 plus or minus 16 (P smaller than 0.001); RVOT (9 patients) 41 plus or minus 10 to 77 plus or minus 22 (P SMALLER THAN 0.001); LVA (5 patients) and LVOT (2 patients), small insignigicant changes. These data indicate that endocardial activation changes can be evaluated in the catheterization laboratory, that right ventricular conduction becomes slower in RBBB as a direct function of total QRS and that left ventricular conduction may be affected when RBBB develops.
Corrected sinus node recovery time. Experimental physiologic and pathologic determinants.
Authors: Chadda K D , Banka V S , Bodenheimer M M , Helfant R H
Published: June 2012

To determine the factors affecting reproducibility of sinus node recovery time, the effects of basic pacing rate, pacing duration, milliamperage, vagal and beta-adrenergic stimulation, and sinud node injury, as well as its instantaneous and daily reproducibility, were studied in 36 anesthetized dogs. Corrected sinus node recovery time (CSNRT) showed a mean variation of 9.8 plus or minus 0.4 msec at an atrial pacing rate of 200 beats/min and 29.8 plus or minus 8 msec at an atrial pacing rate of 140 beats/min (P smaller than 0.05). CSNRT increased progressively from 55.4 plus or minus 10 msec to 103.7 plus or minus 13 msec with increase in pacing rate from 140 beats/min to 200 beats/min. It was reproducible when atrial pacing was carried out for 1-5 min, although a wide variation (10-30 msec) was seen from 7-60 minutes (P smaller than 0.05). This measurement was reproducible on two consecutive days and was unaffected by changes in milliamperage. Vagal stimulation consistently prolonged the CSNRT while beta-adrenergic stimulation decreased it from 132.9 plus or minus 34.5 msec to 50.0 plus or minus 6.5 msec. Sinus node injury consistently prolonged CSNRT at all paced rates. In summary, CSNRT is reproducible only if the same pacing rate and duration are utilized. Since vagal stimulation and sinus node injury prolong this measurement while beta-adrenergic stimulation shortens it, an "abnormal" CSNRT should be assessed in terms of the possible influence of the autonomic nervous system as well as sinus node dysfunction per se.
Echocardiography manifestations of flail aortic valve leaflets in bacterial endocarditis.
Authors: Wray T M
Published: June 2012

This report describes the echocardiographic features seen in a case of bacterial endocarditis in which the aortic valve leaflets had been partially destroyed. The endocardiogram demonstrated unusual, disorganized echo patterns in the outflow tract of the left ventricle near the anterior leaflet of the mitral valve in diastole. These were shown to be continuous with similar disorganized echo patterns demonstrated in the aortic root in diastole. These echocardiographic abnormalities were no longer present after aortic valve replacement.
Cardiac specific creatine phosphokinase isoenzyme in the diagnosis of acute myocardial infarction.
Authors: Varat M A , Mercer D W
Published: June 2012

The specific and sensitivity of serum creatine phosphokinase cardiac specific isoenzyme (MB) in the diagnosis of acute myocardial infarction (AMI) was evaluated. An ion-exchange chromatographic technique was used to isolate MB. Sera layered on mini-columns of DEAE-Sephadex were eluted with Tris-buffered sodium chloride. Quantification of isolated MB was performed by creatine phosphokinase (CPK) assay (Rosalki method) of column effluents. MB was expressed as a percentage of the simultaneously determined total serum CPK; MB was determined in 100 consecutive admissions to the Coronary Care Unit. Acute myocardial infarction was diagnosed by accepted criteria. In 47 patients with proven AMI, including three with normal total CPK, peak MB was greater than 4% of total CPK. In 49 patients without AMI, including 15 with elevated total CPK (due to trauma, injections, cardioversion), peak MB was less than 2% of total CPK. MB was elevated, but did not peak in four patients without AMI but with chronic atrial fibrillation. Isolation and quantification of MB by this technique is rapidly and easily performed and provides a specific and extremely sensitive tool for the diagnosis of AMI.
Time course and zonal variations of ischemia-induced myocardial cationic electrolyte derangements.
Authors: Lie J T , Pairolero P C , Holley K E , McCall J T , Thompson H K , Titus J L
Published: June 2012

Myocardial cationic electrolytes were determined at regular time intervals up to 24 hours after coronary artery ligation in the dog. Replicate electrolyte ratios were computed for different areas of the heart at each time interval. For purposes of statistical analysis, ratios from two border areas and four areas remote from the infarct were pooled as values for ZONE B and ZONE N, respectively, and compared with those from the infarct proper, ZONE I. Ischemia-induced tissue Mg++/Ca++ changes paralleled those of K+/Na+ with respect to time course and zonal variations. In ZONE I, both K+/Na+ and Mg++/Ca++ fell precipitously during the first hour, and the falls became more gradual thereafter, approac hing those of extracellular fluid at 24 hours. Changes in ZONE B, which appeared normal histologically, followed a similar downward trend but differed in magnitude from those in ZONE I (P smaller than 0.01). Changes in ZONE N were small but did not always overlap values in sham-operated dogs. It was concluded that lowered tissue K+/Na+ and Mg++/Ca++ were sensitive, but not specific, indices of myocardial ishemia, and multiple samplings of ionic ratios were essential for proper interpretation of ischemia-induced myocardial electrolyte derangements.
Right heart volume characteristics in transposition of the great arteries.
Authors: Graham T P , Atwood G F , Boucek R J , Boerth R C , Nelson J H
Published: June 2012

Right and left heart volume data were obtained during 44 cardiac catheterizations in 24 patients with complete transposition of the great arteries (TGA) prior to "corrective surgery." Patients were divided into three hemodynamic groups: I)TGA with intact ventricular septum, N = 23 studies in 13 patients, ages 1 day-22 months; II)TGA with ventricular septal defect (VSD), N = 12 studies in six patients, ages 7 days-15 months; III)TGA with VSD plus pulmonary stenosis, N = 9 studies in five patients, ages 5 days-5.6 years. In group I, right ventricular end-diastolic volume (RVEDV) averaged 170 plus or minus 52% of normal (P smaller than 0.001), RV ejection fraction (EF) was 0.48 plus or minus 0.09, 74% of normal (P smaller than 0.001), and RV systolic output (SO) was 123 plus or minus 34% (NS). In group II, RVEDV was 163 plus or minus 25% of normal (P smaller than 0.001), RVEF 0.59 plus or minus 0.08, 91% of normal (NS), and RVSO was 158 plus or minus 52% (P smaller than 0.02). In group III, RVEDV averaged 124 plus or minus 26% of normal (P smaller than 0.04), RVEF 0.58 plus or minus 0.15, 89% of normal (NS), and RVSO 125 plus or minus 57% (NS). Right atrial maximal volume was increased in 21 or 22 studies and averaged 185 plus or minus 47% of normal (P smaller than 0.001). RVEDV was greater than left ventricular end-diastolic volume in all but one patient in group I, but RVEDV/LVEDV was smaller than 1.00 in four VSD patients with very large pulmonary flows. A majority of patients with TGA without VSD have abnormal right heart function as indicated by an increased RVEDV and a low ejection fraction. Longitudinal studies of right ventricular performance in these patients continue to be important in assessment of current methods of therapy.
Seven-year follow-up of cardiovascular study and maximal exercise of Chinese men.
Authors: Bruce R A , Pao Y L , Ting N , Chiang B N , Li Y B , Alexander E R , Beasley R P , Fisher L D , Chiang S T
Published: June 2012

A seven-year follow-up in 1973 of a prospective cardiovascular study of 1820 initially, healthy, middle-aged Chinese men of 40-59 years of age identified 1745 (95.9%) known survivors, 49 (2.7%) interim deaths, and 26 (1.4) who could not be traced. Of the survivors, 1462 (83.8%) were re-examined, 292 (16.7%) had another treadmill test of maximal exercise, and 283 (16.2%) failed to return for re-examination. On the basis of interim surveillance of hospital admissions, questionnaires and re-examination, a greater incidence of noncardiovascular events (338 or 18.6%) than evidence of cardiovascular disease (220 or 12.1%) was found while the majority (1021 or 56.1%) remained healthy. Total mortality was 0.29 for men under 50 and 0.76 per 100 person-years for men of 50 or more years of age. Only nine, or 18.4% of the deaths were due to cardiovascular causes, and unexpectedly for this population sample, only three were attributed to stroke. When cardiovascular morbidity was related to presence of ST depression after maximal exercise, to hypertension at rest by WHO criteria, to both findings, or to absence of either on initial intake examination, incidence increased from 2.3% for NEITHER group, to 5.7% for ST group, to 11.9% for HT group, and to 25.0% for BOTH groups. Re-examination revealed more evidence of cardiovascular disease than did surveillance of hospital admissions. Additional to effects of aging and mild adiposity, longitudinal changes in blood pressure and ST depression, increasing in the NEITHER group, but less frequent in the other groups, showed some evidence of regression toward the mean, as well as emerging disease and the confounding effects of uncontrolled treatment of hypertension in many. The potential for prediction of subsequent cardiovascular morbidity or mortality appeared stronger for hypertension than for postexertional ST depression, although the two were additive in this population, which is more prone to hypertension and stroke but now is developing clinical manifestations of coronary heart disease more frequently.