bluuebunny/crossref_metadata_2025 huggingface dataset:
Improvement of myocardial perfusion and left ventricular function after coronary artery bypass grafting in patients with unstable angina.
Authors: Kolibash A J , Goodenow J S , Bush C A , Tetalman M R , Lewis R P
Published: June 2012

Changes in myocardial perfusion and left ventricular function were evaluated pre- and post-operatively (3--6 months) in 14 patients with unstable angina who underwent coronary artery bypass surgery. Perfusion was studied with intracoronary and intragraft injections of radiolabeled macroaggregated albumin particles. Of 20 abnormal perfusion areas identified preoperatively, 13 demonstrated improved perfusion post-operatively. Segmental analysis of the left ventriculogram demonstrated improved wall motion in 29 abnormally contracting segments; 18 normalized. Areas which showed improvement of left ventricular perfusion were invariably associated with improvement of left ventricular wall motion. Five patients showed improvement in perfusion and contraction in areas of apparent old myocardial infarction. Thirteen of the 14 patients had significantly less angina whether or not there was evidence of improved perfusion. However, only those patients who demonstrated improved perfusion had a significant improvement in their treadmill exercise tolerance postoperatively. Thus, patients with unstable angina have perfusion defects which may be reversed as a result of saphenous vein graft surgery. Reversal of these perfusion abnormalities results in improved left ventricular performance and better exercise tolerance postoperatively.
Effect of filming projection and interobserver variability on angiographic biplane left ventricular volume determination.
Authors: Rogers W J , Smith L R , Hood W P , Mantle J A , Rackley C E , Russell R O
Published: June 2012

Although biplane right anterior oblique-left anterior oblique (RAO/LAO) quantitative left ventricular (LV) angiography is commonly performed, justification of LV volume calculation using the area length method (originally formulated from anteroposterior-lateral (AP/LAT) angiograms) has been limited. To assess whether RAO/LAO and AP/LAT LV volumes are similar when computed by the area length method formula, we performed biplane cine LV angiography in both RAO/LAO and AP/LAT projections in random sequence in 21 patients and four LV models of known volume. LV silhouettes were drawn independently by two trained observers. Calculated angiographic volume of the models correlated almost exactly with their true volume (r = 0.999), establishing the absolute accuracy of this system. Rotation of the LV models through 90 degrees of obliquity at 10 degree increments demonstrated a mean change from true volume of only -5.4 +/- 0.7% (p less than 0.001). In the patient studies, rotation to the 30 degree RAO/60 degree LAO position was associated with significant changes in magnitude of biplane areas and long axes, but area length volume estimates were unchanged. Excellent correlation was found between area length calculated AP/LAT and RAO/LAO volumes with r = 0.90, 0.97, and 0.91 for end-diastolic volume (EDV), end-systolic volume (ESV) and ejection fraction (EF), respectively. Furthermore, interobserver agreement in volume assessment was excellent, with r = 0.98, 0.99, and 0.94 between observers for EDV, ESV, and EF, respectively. Interobserver and inter-method variability for estimates of LV volume and EF ranged from 5--10%. We conclude that when using RAO/LAO LV angiography, volume calculation by the area length method is justified.
Use of combined diet and colestipol in long-term (7--7 1/2 years) treatment of patients with type II hyperlipoproteinemia.
Authors: Kuo P T , Hayase K , Kostis J B , Moreyra A E
Published: June 2012

Long-term effects of diet and colestipol (a bile acid sequestrant) were studied in 25 patients with familial type II hyperlipoproteinemia. Serum lipids and body weights of an initial group of 30 patients were stabilized by low cholesterol-saturated fat-refined carbohydrate diet and the patients were then randomized into placebo and drug-treatment groups. After explaining that the drug is nontoxic and effective in lowering serum lipids, total cholesterol (C) and low-density lipoprotein cholesterol (LDL-C), colestipol (30 g/day) and diet were given to the 25 patients who remained in the long-term follow-up program. The treatment resulted in highly significant lowering of serum lipids (mg/dl, mean +/- SEM): C and LDL-C from 412.7 +/- 24.4 and 331.1 +/- 22.8 to 270 +/- 11.0 and 188.1 +/- 13.8, respectively (p less than 0.001 in each instance) over 7--7 1/2 years. Although we observed no absolute increase in high density lipoprotein (HDL), the HDL/LDL ratio was elevated. Long-term colestipol and diet treatment reduced the xanthoma size and stabilized serially angiographically visualized atherosclerotic lesions in 21 of the 25 patients who showed a satisfactory hypolipemic response. It did not cause nutritional or metabolic disturbances.
Electrophysiological effects of disopyramide in patients with bundle branch block.
Authors: Desai J M , Scheinman M , Peters R W , O'Young J
Published: June 2012

Electrophysiological studies were performed in 22 patients with intraventricular conduction delay before and after intravenous infusion of disopyramide (Norpace), 2 mg/kg. Mean control maximal sinus node recovery time (1039 +/- 187 msec), atrioventricular nodal conduction time (113 +/- 28 msec), and atrioventricular nodal effective refractory periods (349 +/- 67 msec) did not change significantly after administration of disopyramide (1073 +/- 284 msec, 112 +/- 31 msec, and 342 +/- 42 msec, respectively). Mean spontaneous cycle length (756 +/- 146 msec) decreased significantly 5 minutes after disopyramide (717 +/- 124 msec) (p less than 0.05), but not after 30 minutes (734 +/- 142 msec). A small but statistically significant (p less than 0.05) increase occurred after disopyramide in the mean atrial effective refractory period (259 +/- 51 to 280 +/- 53 msec), ventricular effective refractory period (253 +/- 23 to 275 +/- 33 msec), as well as the relative refractory period of the ventricular specialized conduction system (six patients) 433 +/- 78 to 479 +/- 62 msec). Although mean control infranodal conduction time (67 +/- 35 msec) increased 5 minutes after disopyramide (79 +/- 41 msec) (p less than 0.001) (18%), no spontaneous episodes of second-degree or third-degree atrioventricular block were observed. In six patients with premature ventricular depolarizations (greater than or equal to 1/min), the arrhythmia was totally abolished in four, markedly reduced in one, and remained unchanged in one. Disopyramide resulted in significant prolongation of infranodal conduction time as well as in atrial and ventricular refractoriness, but nevertheless appears to be safe in patients with bundle branch block.
Electrophysiologic effects of disopyramide phosphate on sinus node function in patients with sinus node dysfunction.
Authors: LaBarre A , Strauss H C , Scheinman M M , Evans G T , Bashore T , Tiedeman J S , Wallace A G
Published: June 2012

The electrophysiologic effects of intravenously administered disopyramide (2 mg/kg) on three parameters of sinus node function were examined in 16 symptomatic patients with sinus node dysfunction. Based on their ECG data before study, patients were subdivided into group A (n = 8), those with sinus pauses and/or sinoatrial (SA) exit block; and group B (n = 8), those with sinus bradycardia. Disopyramide shortened spontaneous cycle length in 10 of 16 patients and lengthened it in six--markedly so (91%) in one patient. Estimated SA conduction time decreased in seven of 14 patients and increased in seven. Two patients developed second degree SA exit block after disopyramide. Maximum sinus node recovery time was prolonged by disopyramide in 11 of 16 patients and markedly so in four. For the group as a whole there was no significant difference in spontaneous cycle length, maximum sinus node recovery time or estimated SA conduction time. P-wave and QRS durations and H-V intervals were significantly lengthened by disopyramide. Marked depression of the three parameters of sinus node function occurred in three group A patients and in one group B patient who had persistent severe sinus bradycardia. These four patients also had secondary pauses after termination of rapid atrial pacing under control conditions. Disopyramide should be administered cautiously to patients with sinus node dysfunction, particularly those with sinus pauses, SA exit block or secondary pauses.
Incidence and site of atrioventricular block in patients with chronic bifascicular block.
Authors: Dhingra R C , Wyndham C , Amat-y-Leon F , Denes P , Wu D , Sridhar S , Bustin A G , Rosen K M
Published: June 2012

Four hundred fifty-two patients with chronic bifascicular block and initially intact atrioventricular (AV) conduction were detected, studied, and prospectively followed between January 1970 and March 1978. There were 360 males and 92 females, ages 18--93 years (mean +/- SD, 62 +/- 15 years). Follow-up ranged from 29-2804 days (mean 1066 +/- 97 days). AV block (2 degrees or 3 degrees) developed in 29 patients, nine with apparent cause and spontaneously in 20. Cumulative annual incidence of all heart block for 1--5 years was, respectively, 4%, 5.9%, 8.7%, 10.1% and 11.3%, and for spontaneous block was 2%, 3.1%, 5.2%, 6.7%, and 7.1%. Sites of spontaneous block were probably or definitely AV nodal in ten, His bundle in one, and trifascicular in nine. Cumulative incidence of AV block in surviving bifascicular block patients is 11% at 5 years, with 7% reflecting spontaneous block. The probable or definite site of AV block varies and is trifascicular in less than half of the patients. The small incidence of trifascicular block probably explains the difficulty in predicting this complication with electrophysiological studies.
Detection of myocardial infarct extension by CK-B radioimmunoassay.
Authors: Rothkopf M , Boerner J , Stone M J , Smitherman T C , Buja L M , Parkey R W , Willerson J T
Published: June 2012

Myocardial infarct extension after the acute event was defined as a second reise in the myocardial isoenzyme of serum creatine kinase (CK-B) after the initial return of CK-B to normal values. In 43 patients with acute myocardial infarcts, CK-B was measured by radioimmunoassay every 12 hours for 14 days. Nineteen patients had anterior transmural myocardial infarcts AMI, 14 had inferior transmural myocardial infarcts (IMI) and 10 had subendocardial myocardial infarcts (SEMI). Infarct extension as detectd by a second rise in serum CK-B occurred in six patients (32%) with AMI, two (14%) with IMI and two (20%) with SEMI; these differences are not statistically significant. Infarct extension for all patients combined was 23%. Four patients with AMI also had infarct extension as determined by recurrent chest pain. ECG alterations and other enzyme changes. In the other six, the infarct extension was undetected clinically. Four patients with AMI and infarct extension died within 3 weeks after hospitalization. We did not note any additional morbidity or mortality in patients with infarct extension who had IMI or SEMI. There was no significant difference in the frequency of previous myocardial infarction, history of hypertension, diabetes mellitus or smoking history in patients with and without infarct extension shown by serum CK-B isoenzyme elevations. The measurement of serum CK-B values with a quantitative and sensitive assay suggests that myocardial infarct extension occurs more commonly than clinically recognized, but the frequency of extension may be less than that reported in patients in whom precordial mapping and total serum CK values were measured to identify this phenomenon.
Effect of beta-adrenergic suppression by propranolol on coronary collateral development in response to chronic coronary ischemia in dogs.
Authors: Neill W A , Nakornchai V , Oxendine J , Paul M S
Published: June 2012

Acute left circumflex coronary artery (LC) occlusion in conscious dogs caused marked ischemia in the myocardium supplied by the occluded artery, as judged by the radioactive microsphere technique for determining blood flow distribution. With the chest open, LC pressure distal to the occlusion fell to 21 +/- 1.9% of aortic pressure. By 8 weeks after gradual LC occlusion with an ameroid constrictor, collateral development had restored coronary blood flow distribution to near-normal under basal conditions and during pacing, at a heart rate of 200 beats/min. The only evidence for ischemia was in the subepicardium within the distribution of the unoccluded left anterior descending artery, which provided the extra collateral blood flow. Distal LC pressure was 70 +/- 1.7% of aortic pressure. Propranolol 160 mg orally every 6 hours for 8 weeks had no detectable effect on coronary collateral development, as judged by blood flow distribution or distal LC pressure. The only significant difference for the propranolol dogs was a slight transmural shift away from the subendocardium in the left anterior descending region.
The syndrome of variant angina culminating in acute myocardial infarction.
Authors: Madias J E
Published: June 2012

Ten patients 28-54 years old with recurrent attacks of variant angina (chest pain associated with transient ST-segment elevation) culminating in acute myocardial infarction were studied. Systemic blood pressure and heart rate remained unchanged or decreased during chest pain. Diagnosis of myocardial infarction was made on the basis of pathognomonic enzyme changes and T-wave inversions persisting for several weeks (seven patients) or development of Q waves (three patients). Complications were similar to the ones previously observed in conventional myocardial infarction. None of these patients died. Past history was characterized by absence of effort angina. Exercise stress testing after infarction was normal, and coronary arteriography revealed a spectrum of pathology, ranging from normal arteriograms to three-vessel disease. Intraaortic balloon pumping was ineffective in two patients, but subsequent coronary bypass surgery shortly after myocardial infarction was not followed by further attacks of chest pain. Follow-up of these patients revealed a benign course. Alcohol drinking and cigarette smoking appeared to be very prevalent in this group.
Increased coronary mortality in relatives of hypercholesterolemic school children: the Muscatine study.
Authors: Schrott H G , Clarke W R , Wiebe D A , Connor W E , Lauer R M
Published: June 2012

From 2,874 school children participating in the 1971 and 1973 Muscatine Coronary Risk Factor Survey, we selected three groups of index cases for detailed family study: the HIGH group (n = 56), with cholesterol levels greater than the 95th percentile twice; the MIDDLE group (n = 46), cholesterol levels between the 5th and 95th percentile; and the LOW group (n = 46), cholesterol levels less than the 5th percentile twice. Coronary mortality determined from death certificates was increased in the young relatives (ages 30-59) of the HIGH group index cases, as follows: twofold excess in HIGH male relatives compared with the MIDDLE or LOW group (p less than 0.05); tenfold excess in the HIGH female relatives compared with the MIDDLE and LOW group combined (p less than 0.01). After correction for years at risk, there was an approximately twofold significantly-increased coronary mortality. Stroke mortality was higher, although not significantly, in the older relatives (ages greater than or equal to 60) of the HIGH index cases. Cancer mortality was not significantly different among the relatives of the three groups of index cases. This study indicates that school children's cholesterol levels cluster with those of their family members and that persistent hypercholesterolemia in children identifies families at risk for coronary artery disease.
Deep venous thrombosis of the upper extremity: a reappraisal.
Authors: Prescott S M , Tikoff G
Published: June 2012

Deep venous thrombosis (DVT) of the upper extremity is an unusual thrombotic event (1-2% of all DVT) which can be conveniently divided into two categories, traumatic (including "stress") and spontaneous. The spontaneous form is not reported as often in the literature, but occurs more commonly than the traumatic form. There is an increased left-sided predominance in spontaneous DVT compared with the traumatic form, where a right-sided predominance exists. Possible anatomical and physiological explanations are offered for the left-sided predominance in spontaneous DVT of the upper extremity. The thrombogenesis of DVT of the upper extremity is compared with DVT of the lower extremity. An analysis of responses to therapy and considerations for other therapeutic approaches are offered.
Contrast M-mode echocardiography in diagnosis of atrial septal defect in acyanotic patients.
Authors: Kronik G , Slany J , Moesslacher H
Published: June 2012

Contrast echocardiograms during normal quiet respiration and during the Valsalva maneuver were performed in 15 patients with atrial septal defect (ASD) by injecting saline solution into an antecubital vein. Contrast shunting (the appearance of contrast echoes in the left heart) was observed not only in four patients with severe pulmonary hypertension (group 2), but also in 11 patients with uncomplicated ASD (group 1). Contrast shunting was prominent in all group 2 patients. In group 1, contrast shunting was sometimes subtle and difficult to recognize, but at other times was very obvious and similar to the findings in group 2. Contrast shunting was generally more pronounced during the Valsalva maneuver than during normal respiration, although there were exceptions. The amount of contrast appearing in the left heart did not correlate with the size of the defect. Small right-to-left shunts which are clinically insignificant but detectable by contrast echocardiography are present, or can be provoked by the Valsalva maneuver, in most patients with ASD. Contrast echocardiography is a useful, noninvasive method to detect interatrial communication, even in acyanotic patients.
Ventricular septal defect in infancy: a combined vectorgraphic and echocardiographic study.
Authors: Riggs T , Mehta S , Hirschfeld S , Borkat G , Liebman J
Published: June 2012

Echocardiograms (echo) and vectorcardiograms (VCG) from 40 infants with ventricular septal defects (VSD) were compared with cardiac catheterization data to assess noninvasively the hemodynamics of VSD. The specific aim was to use VCG parameters of right ventricular hypertrophy and echo parameters which reflect pulmonary artery pressure to identify all patients with a nonrestrictive VSD. The configuration of the QRS vector in the horizontal plane was more reliable than individual voltages in assessing right ventricular systolic pressure. Among patients older than 2 months with a clockwise or anterior two-main-vector horizontal loop, 73% (eight of 11) had a nonrestrictive VSD. However, a counterclockwise or posterior two-main-vector loop was also frequently found (43%, six of 14) in infants with a nonrestrictive VSD. The most useful echo parameter was the ratio of right ventricular preejection period-to-right ventricular ejection time (RPEP/RVET), which closely (r = 0.74) reflected the pulmonary artery diastolic pressure. An elevated RPEP/RVET to greater than 0.30 was always associated with a nonrestrictive VSD, although many patients (36%, five of 14) with a nonrestrictive VSD had a normal ratio. By combining both echo and VCG parameters, a nonrestrictive VSD was correctly identified in all patients, while a restrictive VSD was correctly identified in 81% (21 of 26).
Right ventricular outflow tract assessment by cross-sectional echocardiography in tetralogy of Fallot.
Authors: Caldwell R L , Weyman A E , Hurwitz R A , Girod D A , Feigenbaum H
Published: June 2012

Cross-sectional echocardiographic (CSE) studies were obtained in 29 children with tetralogy of Fallot. In this study we evaluated the capability of CSE to record the right ventricular outflow tract (RVOT) and compared the severity of infundibular obstruction determined by CSE with cineangiographic (cine) determinations. In addition, we examined capabilities of CSE and M-mode echocardiography (M-mode) to record the diagnostic features of tetralogy of Fallot, including RVOT obstruction, aortic overriding, ventricular septal defect, and presence of the pulmonary valve. An excellent correlation (r = 0.925) was found for the combined pre- and post-repair patients studied by CSE vs cine, while the correlation (r = 0.805) for M-mode was not as good. The difference was even more striking for the unrepaired patients, in which the correlation (r = 0.746) for CSE was much better than for M-mode (r = 0.374). In the unrepaired patients, CSE allowed easier detection of the ventricular septal defect than M-mode (95% for CSE vs 76% for M-mode). The pulmonary valve was recorded in 90% by CSE, but in only 26% by M-mode. Aortic overriding was recorded in all unrepaired patients both by CSE and M-mode. These data indicate that CSE is better than M-mode for recording the RVOT dimensions, ventricular septal defect, and the pulmonary valve in unrepaired patients with tetralogy of Fallot.
Ventricular aneurysms complicating coxsackievirus group B, types 1 and 4 murine myocarditis.
Authors: El-Khatib M R , Chason J L , Lerner A M
Published: June 2012

Suckling Swiss Webster mice were inoculated with 10(4)TCD50 of coxsackieviruses, group B types 1 or 4. Virulent necrotizing myocarditis resulted in 185 infected mice. Of the latter group, three (14.3%) nurslings on the 17th and 23rd day after inoculations had left ventricular aneurysms postmortem. None of 61 concurrently matched control mice developed aneurysms. Ventricular aneurysm is a suggested but previously undocumented complication of murine, and possibly human necrotizing transmural coxsackievirus myocarditis.
Long-term changes in mitral valve area after successful mitral commissurotomy.
Authors: Heger J J , Wann L S , Weyman A E , Dillon J C , Feigenbaum H
Published: June 2012

We examined the long-term effects of closed instrumental mitral commissurotomy on mitral valve area (MVA) in 18 patients, followed for as long as 14 years after successful operation. Each patient had preoperative and early postoperative cardiac catheterization; late postoperative determination of MVA was obtained 10-14 years (mean 12.2 years) after commissurotomy. In 17 patients, the MVA was determined by cross-sectional echocardiography and in one patient by repeat cardiac catheterization. Thirteen of 18 patients had no change in MVA between early postoperative study (mean MVA = 2.7 cm2) and late postoperative study (mean MVA = 2.9 CM2). MVA in five patients decreased 0.7-2.2 cm2 (mean 1.4 cm2) during the follow-up period. In these five patients, the mean MVA at early postoperative study was 2.7 cm2 and at late postoperative study was 1.3 cm2 (p less than 0.001). At late postoperative evaluation, cardiac symptoms were associated with severity of mitral stenosis but did not predict restenosis. A successful, closed, instrumental mitral commisurotomy can provide substantial long-term improvement in MVA.
Instantaneous transmitral blood flow and anterior mitral leaflet motion in man.
Authors: Laiken S L , Johnson A D , Bhargava V , Rigo P
Published: June 2012

Transmitral blood flow was measured in man by numerical differentiation of left ventricular volume as a function of time in 11 patients undergoing cardiac catheterization. Using this technique, transmitral blood flow may be studied in a variety of pathologic states without the need for surgically introduced flowmeters. Just before left ventriculography, echocardiography of the mitral valve was performed. The pattern of transmitral blood flow was strikingly similar to the diastolic movement of the anterior mitral leaflet. At any equivalent diastolic filling time, the percent of the integrated area beneath the curve inscribed by the diastolic anterior mirtal leaflet echoes closely approximated the percent of stroke volume which had entered the left ventricle. This observation supports the hypothesis that mitral leaflet motion accurately reflects transmitral flow. Consequently, at a given time during diastole, the relative velocity of transmitral flow and the percent of the stroke volume which has entered the left ventricle may be approximated noninvasively from the anterior mitral leaflet echogram.
Subxiphoid cross-sectional echocardiography in infants and children with congenital heart disease.
Authors: Lange L W , Sahn D J , Allen H D , Goldberg S J
Published: June 2012

We developed anatomically related cross-sectional echocardiographic views to image the heart from the subxiphoid area in 100 children and infants with various forms of congenital heart disease studied prospectively before cardiac catheterization. Wide-angle cross-sectional views were achieved using a mechanical sector scanner in a scan plane oriented parallel to a line between the patient's shoulders (a coronal plane) showing the equivalent anatomy of an anteroposterior angiogram. The subxiphoid technique appeared to be better than chest wall-based imaging in demonstrating obstructive lesions in the proximal portion of the right ventricular outflow tract (19 patients), i.e., the subpulmonic area, which is often at the narrow edge of the sector and behind the transducer artifact in chest wall studies. The subxiphoid technique was also useful for imaging the interatrial and interventricular septae; in subxiphoid views, as opposed to four-chamber apical views, there was significantly less false septal dropout and atrial septal defects (19 patients) as well as ventricular septal aneurysms (seven patients) were easily imaged. Finally, the subxiphoid orientation provided more adequate imaging in patients with discrete diaphragmatic subaortic stenosis (four patients), even when the diaphragm was just beneath the aortic valve. Subxiphoid cross-sectional echocardiography is an easily understood anatomical format for imaging cross-sectional anatomy in congenital heart disease and is a valuable adjunct to cross-sectional echocardiography from the chest wall.
Pulmonary vascular disease in transposition of the great vessels and intact ventricular septum.
Authors: Newfeld E A , Paul M H , Muster A J , Idriss F S
Published: June 2012

Eight of 135 (6%) children with d-transposition of the great vessels and with intact ventricular septum and no patent ductus arteriosus had evidence of progressive pulmonary vascular disease. Seven of 101 (7%) patients for whom histologic data was available, had Heath-Edwards grades IV or V pulmonary vascular disease, six had grade II, and 88 had either normal or grade I findings. One of 34 patients for whom histologic data was not available had hemodynamic evidence of pulmonary vascular disease at cardiac catheterization after the Mustard operation. When infants younger than 3 months old were excluded, eight of 85 (9%) had advanced pulmonary vascular disease. Twenty-three patients had microthrombi in their pulmonary arteries and arterioles, and in one patient thrombi were observed before the development of pulmonary vascular disease. Clinically unrecognized pulmonary microthrombi are suggested as a possible etiologic agent in the development of pulmonary vascular disease in patients with transposition of the great vessels. Progressive pulmonary vascular disease can first be discovered after the Mustard operation, even in patients without preoperative evidence of pulmonary hypertension or elevated pulmonary vascular resistance.
Preeminence of the left stellate ganglion in the long Q-T syndrome.
Authors: Crampton R
Published: June 2012

In seven patients with Romano-Ward syndrome, stellate ganglion block or stimulation and pharmacologic interventions were made to assess their influence on duration of the O-T interval, electrical alteration of the T wave and ventricular tachydysrhythmias. Left stellate ganglion block and right stellate ganglion stimulation shortened Q-T interval, abolished alternans phenomena and suppressed tachydysrhythmias. Propranolol and phenytoin had a similar effect. In contrast, right stellate ganglion block, left stellate ganglion stimulation and prior administration of quinidine and procainamide had an opposite effect. These responses resemble observations in animal models which suggest that excessive or unopposed activity of the left, or subnormal activity of the right stellate ganglion, or both, account for the pathophysiologic manifestations of the long Q-T syndrome. They are also consistent with clinically correlated, cardiac neuropathologic findings in these patients. An analogous but acquired dysautonomia involving the left stellate ganglion and ischemic left ventricle may precipitate sudden coronary death.
Usefulness and limitations of thallium-201 myocardial scintigraphy in delineating location and size of prior myocardial infarction.
Authors: Niess G S , Logic J R , Russell R O , Rackley C E , Rogers W J
Published: June 2012

In order to evaluate the usefulness of thallium-201 (201TI) myocardial scintigraphy in delineating the location and size of prior myocardial infarction, 32 patients were evaluated at a mean of 7 +/- 2 months after infarction with a 12-lead ECG, resting 201TI myocardial scintigram, biplane left ventriculogram and coronary angiograms. From the left ventriculogram, asynergy was quantified as percent abnormally contracting segment (% ACS), the percent of end-diastolic circumference which was either akinetic or dyskinetic. Using a computerized planimetry system, we expressed 201TI perfusion defects as a percentage of total potential thallium uptake. Of 21 patients with ECG evidence of prior transmural infarction, a 201TI defect was present in 20 (95%), and angiographic asynergy was present in all 21 (100%). The site of prior infarction by ECG agreed with the 201TI defect location in 24 of 32 patients (75%) and with site of angiographic asynergy in 23 of 32 patients (72%). Scintigraphic defects were present in only four of 10 patients (40%) with ACS less than or equal to 6%, but scintigraphic defects were found in 20 to 22 patients (91%) with ACS greater than 6% (p less than 0.01). Thallium defect size correlated marginally with angiographic left ventricular ejection fraction (r = -0.60) but correlated closely with angiographic % ACS (r = 0.80). Thallium defect size was similar among patients with one-, two-, or three-vessel coronary artery disease (greater than or equal to 70% stenosis), but thallium defect size was larger in patients with electrocardiographic evidence of transmural infarction (p less than 0.01) or pulmonary capillary wedge pressure greater than 12 mm Hg (p less than 0.001). Thus, resting 201TI myocardial scingigraphy is useful in localizing and quantifying the extent of prior myocardial infarction, but is insensitive to small infarcts (ACS less than 6%).
The role of left ventricular conduction in the electrogenesis of left ventricular hypertrophy. An electrophysiologic study in man.
Authors: Piccolo E , Raviele A , Delise P , Dainese F , Pascotto P , Totaro G , Sartori F , D'Este D
Published: June 2012

Various electrocardiographic and vectorcardiographic (ECG-VCG) patterns of ventricular conduction disturbances are inducible by premature right atrial stimulation (PRAS). These patterns are a consequence of different degrees of refractoriness in the specialized ventricular conduction system. We observed that the intermediate phase of left bundle branch block (LBBB) induced by PRAS in 20 subjects with normal basal QRS (complexes) were similar to those of left ventricular hypertrophy (LVH). In 18 patients with basal ECG-VCG signs of LVH, right bundle branch block (RBBB) induced by PRAS produced a progressive disappearance of these signs and the "normalization" of the tracings. The initial maximum QRS vector decreased, disappeared or remained absent in the patients with LBBB induced by PRAS, and appeared (when absent in the basal VCG) and remained unchanged (when present) in patients with RBBB induced by PRAS. In this paper we discuss the electrogenetic implications of these data. The ECG-VCG sings of LVH are probably dependent on a slowed conduction in the left bundle branch system, while anatomical hypertrophy per se probably plays a less important role.
Congenital coronary arteriovenous fistula. Report of 13 patients, review of the literature and delineation of management.
Authors: Liberthson R R , Sagar K , Berkoben J P , Weintraub R M , Levine F H
Published: June 2012

Thirteen new patients and 174 patients previously reported with coronary arteriovenous fistula (CAVF) were reviewed to delineate the course and management of CAVF and to clarify the role of surgical ligation in the young asymptomatic patient. Patients were grouped according to age: 99 patients (four new and 95 reported) were less than 20 years old and 88 (nine new and 79 reported) were greater than or equal to 20 years old. Of those under 20 years of age, 19% had preoperative symptoms or CAVF-related complications, including congestive heart failure (CHF) in 6%, subacute bacterial endocarditis in 3% and death in one patient. Seventy-six patients younger than 20 years old had CAVF ligation with only one significant complication. In contrast, 63% of the older group and all of our nine older patients had preoperative symptoms or complications, including CHF in 19%, SBE in 4%, myocardial infarction (MI) in 9%, death in 14% and fistula rupture in one patient. Of the 43 ligated older patients, 23% had surgical complications, including MI in three and death in three. Mean pulmonic-to-systemic flow in the entire group was 1.6:1 and did not differ significantly in those with or without symptoms or complications. One of our patients and one previously reported had spontaneous CAVF closure. In summary, early elective ligation of CAVF is indicated in all patients because of the high incidence of late symptoms and complications and the increased morbidity and mortality associated with ligation in older patients.
Prevalence of arrhythmias during 24-hour electrocardiographic monitoring and exercise testing in patients with obstructive and nonobstructive hypertrophic cardiomyopathy.
Authors: Savage D D , Seides S F , Maron B J , Myers D J , Epstein S E
Published: June 2012

Many patients with hypertrophic cardiomyopathy die suddenly and unexpectedly, a significant number perhaps due to arrhythmia. Of 100 patients initially evaluated for signs or symptoms suggestive of heart disease or a family history of hypertrophic cardiomyopathy, 51 were selected solely because they met the echocardiographic criteria for the disease, and 49 patients were selected primarily because they had: 1) normal sinus rhythm despite left atrial enlargement, 2) a history of syncope, 3) a family history of premature death, or 4) a history of paroxysmal atrial fibrillation. All 100 patients were studied by 24-hour ambulatory electrocardiographic monitoring and 74 of them also underwent treadmill exercise testing. More than 50% of patients in repetitive ventricular premature depolarizations, including 19% who had ventricular tachycardia. Monitoring was superior to exercise testing for exposing these arrhythmias. Two patients experienced cardiac arrest within 2 months of monitoring; in each, monitoring had revealed ventricular tachycardia. Two patients with paroxysms of supraventricular tachycardia during monitoring developed fixed atrial fibrillation within 1 year. These preliminary observations suggest that monitoring may help identify patients at increased risk for significant arrhythmic events.
Echocardiographic evaluation of ventricular septal aneurysms.
Authors: Snider A R , Silverman N H , Schiller N B , Ports T A
Published: June 2012

The spontaneous closure of ventricular septal defects is frequently associated with septal aneurysm formation. In this paper we discuss the M-mode and two-dimensional echocardiographic findings in nine children with aneurysms of the ventricular septum in association with ventricular septal defects. In all patients the diagnosis was confirmed by angiography. The ventricular septal aneurysms were detected by both M-mode and two-dimensional echocardiography. With M-mode echocardiography, septal aneurysms could be recognized by a pattern of multiple systolic echoes within the right ventricle. With two-dimensional echocardiography, the protrusion of the septal aneurysm into the right ventricle could be seen from several views and the location and the relative size of the aneurysm assessed. Echocardiographic techniques useful in the detection of ventricular septal aneurysms are discussed and examples presented.
Comparison of cardiovascular responses to static-dynamic effort and dynamic effort alone in patients with chronic ischemic heart disease.
Authors: DeBusk R , Pitts W , Haskell W , Houston N
Published: June 2012

Thirty men, mean age 55 years, known to have treadmill-induced ischemic ST-segment depression, performed static and dynamic effort, i.e., forearm lifting and treadmill exercise, separately and combined. Static effort was sustained at 20%, 25% or 30% of maximal forearm lifting capacity. Two symptom-limited treadmill tests, one with and one without added static effort, were performed on each of two visits. Compared with dynamic effort alone, combined static-dynamic effort decreased treadmill work load and increased heart rate, systolic blood pressure and rate-pressure product at the onset of ischemic ST-segment depression or angina pectoris: 7.1 +/- 0.4 vs 8.0 +/- 0.5 (SEM) multiples of resting oxygen consumption (mets), estimated; 141 +/- 3 vs 134 +/- 3 beats/min; 170 +/- 4 vs. 162 +/- 4 mm Hg and 239 +/- 8 vs 218 +/- 9 (p less than 0.001). The prevalence of angina pectoris was significantly less with combined static-dynamic effort than with dynamic effort alone. Static effort causes a resetting of the threshold at which ischemic abnormalities appear during dynamic effort.
Quantitative left ventricular wall motion analysis: a comparison of area, chord and radial methods.
Authors: Gelberg H J , Brundage B H , Glantz S , Parmley W W
Published: June 2012

We were interested in divising a relatively simple quantitative technique that could be used on a routine clinical basis for wall motion analysis. Three quantitative methods of left ventricular (LV) regional analysis were compared in the 30 degrees right anterior oblique and 60 degrees left anterior oblique projection. The control group consisted of 17 patients with qualitatively normal LV wall motion; the abnormal group comprised 17 patients with at least one region of severe, qualitative wall motion abnormality. Normal regional values were determined for area, chord and radial methods by applying the techniques to the ventriculograms of the control group. Each technique was then applied to the abnormal group's ventriculograms to determine the percentage of qualitatively abnormal regions not detected by each method. The area method had the lowest failure rate (p less than 0.001) and the best separation of measured normal and abnormal regions' ejection changes (p less than 0.001), and best reflected symmetric uniform motion of the ventricular silhouette. We conclude that the area method, of the techniques examined, was best for the quantitative analysis of LV wall motion abnormalities.
Amrinone: a new non-glycosidic, non-adrenergic cardiotonic agent effective in the treatment of intractable myocardial failure in man.
Authors: LeJemtel T H , Keung E , Sonnenblick E H , Ribner H S , Matsumoto M , Davis R , Schwartz W , Alousi A A , Davolos D
Published: June 2012

Chronic congestive heart failure not controlled by conventional therapy was treated with intravenous amrinone, a new non-glycosidic, non-catecholamine cardiotonic agent. Eight patients with New York Heart Association functional class III-IV symptoms were hemodynamically monitored. At peak effect, cardiac index (CI) increased from 1.84 +/- 0.32 to 2.74 +/- 0.44 l/min/m2 (mean +/- SD) (p less than 0.001) and left ventricular filling pressure (LVFP) decreased from 25.8 +/- 6.2 to 19.5 +/- 6.8 mm Hg (p less than 0.05), while heart rate and mean aortic blood pressure did not change significantly. Mean endocardial circumferential fiber shortening (mean Vcf), determined by echocardiography, increased from 0.61 +/- 0.27 to 0.89 +/- 0.34 cir/sec (p less than 0.05). The duration of action after bolus infusion varied from 60--90 minutes. During continuous infusion of amrinone, sustained increases in CI and reductions in LVFP, similar to those at the time of peak effect after bolus administration, were maintained for 180 minutes. These marked cardiotonic effects of amrinone in patients already taking digitalis for severe heart failure occurred without side effects of arrhythmias or altered arterial pressures. The fact that the drug is orally active makes amrinone a v:ry promising inotropic agent for the treatment of chronic heart failure in man.
Mechanism of propranolol withdrawal phenomena.
Authors: Nattel S , Rangno R E , Van Loon G
Published: June 2012

Nine patients on chronic treatment with propranolol for essential hypertension for 3 months or longer were studied after abrupt discontinuation of the drug. Each patient demonstrated transient supersensitivity to the chronotropic effects of isoproterenol, beginning 2--6 days (median 4 days) after propranolol withdrawal, lasting for 3--13 days (median 6 days), with the maximum sensitivity on day 6. A significantly lower dose of isoproterenol was necessary to increase heart rate 25 beats/min on day 6 (median dose 1.2 microgram, range 0.3--3.4 microgram) compared with after day 14, when sensitivity had stabilized (median dose 2.3 microgram, range 1.4--7.6 microgram). Six patients had transient symptoms (headache, chest pain, palpitations and sweating) after abrupt propranolol withdrawal, coinciding with supersensitivity to isoproterenol in five. Transient increases in plasma catecholamines and blood pressures and sustained increases in heart rate occurred during the period of isoproterenol supersensitivity in most patients, and may have contributed to symptoms noted. The delayed onset and potentially long duration of beta-adrenergic supersensitivity after abrupt propranolol withdrawal have important clinical implications.
The Use of an Oximetrically Determined Circulation Time from the Right Ventricle to the Ear in Congenital Heart Disease
Authors: LASSER RICHARD P. , GORDON ALVIN J. , BORUN RAYMOND , KING FREDERICK H.
Published: June 2012

Evans Blue (T-1824) was injected into the right ventricle through a cardiac catheter and the time of the arrival of dye at the ear was measured with an oximeter. This circulation time appeared to indicate reliably the presence of venoarterial shunting through an over-riding aorta. The difficulties ordinarily encountered in positive identification of this defect are discussed. The importance of the identification, particularly with regard to the differential diagnosis between tetralogy of Fallot and pulmonary stenosis with an interatrial communication, is stressed.
The Effect of Arterialization of the Coronary Sinus in Dogs on Mortality Following Acute Coronary Occlusion
Authors: ECKSTEIN R. W. , SMITH GEORGE , ELEFF MORTON , DEMMING JAMES
Published: June 2012

The mortality rates were determined in two groups of dogs following acute circumflex artery occlusion. Both groups were surgically prepared in the same manner. In a group of 20 dogs the coronary sinus was cannulated to divert the blood into the left jugular vein. Circumflex artery ligation resulted in 70 per cent mortality within one hour. In a second group of 10 dogs the coronary sinus was arterialized from the left subclavian artery and the sinus mean pressure was held at 50 mm. Hg. In this group circumflex artery ligation resulted in 100 per cent survival for one hour. Statistical analysis shows the results to be highly significant. The results strongly suggest that arterialization of the coronary sinus protects the hearts of dogs from ventricular fibrillation following coronary artery ligation.
Clinical Studies on Veratrum Alkaloids
Authors: MEILMAN EDWARD , KRAYER OTTO
Published: June 2012

An extensive study of the hypotensive properties of protoveratrine, a pure crystalline ester alkaloid from
Veratrum album
, has been made in hypertensive and normotensive individuals. This drug is shown to be capable of lowering the blood pressure in hypertension of varied etiologies including essential hypertension, acute or chronic renal disease, malignant hypertension, toxemia of pregnancy, and carcinoma of the adrenal cortex. The relationships between dose and response from single intravenous, continuous intravenous, intramuscular and oral administration have been determined.
The Lewis A. Conner Memorial Lecture
Authors: BLUMGART HERRMAN L. , FREEDBERG A. STONE
Published: June 2012

The physiologic, pathologic, and clinical interrelationships between the thyroid and the cardiovascular system are discussed. The therapeutic effects of hypothyroidism induced by I
131
to lessen the work of the heart are described in 39 euthyroid patients with intractable advanced angina pectoris or congestive failure. Only patients were treated who were seriously incapacitated despite all conventional forms of therapy for many months or years. The results of two confirmatory series of cases similarly treated by others are reviewed.
Paradoxic Action of Amyl Nitrite in Coronary Patients
Authors: CONTRO STEPHEN , HARING OLGA M. , GOLDSTEIN WALTER
Published: June 2012

Amyl nitrite inhalation in patients with sclerotic coronary vessels is followed by electrocardiographic changes typical of temporary coronary insufficiency. It is suggested that, in such cases, a slight increase of cardiac work (tachycardia) together with a decrease of blood supply (fall in blood pressure), leads to myocardial ischemia. Comparison between an exercise test and amyl nitrite inhalation in the same patients indicates similar results. Amyl nitrite inhalation may be used as a simple functional test in borderline or questionable cases of coronary heart disease.
The Blood Flow through the Calf of the Leg during Acute Occlusion of the Femoral Artery and Vein
Authors: SHEPHERD JOHN T.
Published: June 2012

The calf blood flow has been studied in the human subject before and during acute occlusion of the common femoral artery and vein. The results suggest that the concomitant venous occlusion has a detrimental effect on the development of the collateral circulation.
Deposition and Disappearance of Digitoxin from the Tissues of the Rat, Rabbit, and Dog after Parenteral Injection
Authors: FRIEDMAN MEYER , ST. GEORGE SHIRLEY , BINE RENÉ , BYERS SANFORD O. , BLAND CATHARINE
Published: June 2012

Digitoxin administered to the rat, rabbit, or dog has no specific avidity for heart muscle. The quantity recovered from this organ at any time was no greater than from liver or kidney, while these organs continued to contain the glycoside for a much longer period of time.
Correlation of Serum Potassium Concentrations with the Blood Pressure in Rats Fed a Potassium-Deficient Ration
Authors: ST. GEORGE SHIRLEY M. , FREED S. CHARLES , ROSENMAN RAY H.
Published: June 2012

Rats which develop low blood pressures as a result of low potassium diet are shown to have lowered serum potassium levels. When the blood pressure is restored to normal by injection and 24 hour feeding of potassium, serum potassium levels also return to normal.
The Measurement of the Q-T Interval of the Electrocardiogram
Authors: LEPESCHKIN EUGENE , SURAWICZ BORYS
Published: June 2012

The sources of error in determination of the beginning of QRS and the end of T during measurement of the Q-T duration are analyzed. An important error is confusion of an elevated U wave with the T wave, resulting in the diagnosis of a prolonged Q-T. In such cases, some of the precordial leads usually show a notch or kink between T and U which indicates approximately the end of T. If these criteria are used, the true corrected Q-T duration in hypopotassemia without hypocalcemia is not prolonged, but normal or shortened, corresponding to an earlier appearance of the second heart sound.