Biomedical subjects

R Gorlin

Publications and source records attributed to R Gorlin.

At least 163 records · Page 9Linked to original sources

PubMed1975

Natural history of S-T segment elevation after acute myocardial infarction.

Clinical, electrocardiographic and cineventriculographic data in two patient groups were analyzed to define the natural history of S-T segment elevation after myocardial infarction. In sixteen of 22 patients (73 percent) with acute inferior myocardial infarction, S-T segment elevation was present on hospital admission, persisting in 1 (5 percent) by the 2nd week. S-T segment elevation was present on admission in 18 of 23 patients (78 per cent) with acute anterior myocardial infarction and persisted in 13 after 1 week and in 9 of 14 (64 percent) during a follow-up period of 1 to 6 months. S-T segment elevation lasting more than 2 weeks after myocardial infarction did not resolve. Compared with patients with inferior myocardial infarction or anterior infarction without persistent S-T segment elevation, patients with anterior infarction and persistent S-T segment elevation had a higher level of mean maximal serum creatine phosphokinase (CPK), more severe left ventricular decompensation and a greater frequency of death in the early follow-up period. In a separate series of 95 patients with cineangiographically documented coronary artery disease, 40 of 65 patients (62 percent) with advanced anterior and apical asynergy had persistent S-T segment elevation. By contrast, only 1 of 30 (3 percent) with coronary disease and normal ventriculograms had persistent S-T segment elevation. We concluded that (1) the natural history of S-T segment elevation after myocardial infarction is resolution within 2 weeks in 95 percent of inferior but in only 40 percent of anterior infarctions; (2) S-T segment elevation persisting more than 2 weeks after myocardial infarction does not resolve; (3) persistent S-T segment elevation is associated with clinically more severe myocardial infarction; and (4) in patients with coronary artery disease, persistent S-T segment elevation after myocardial infarction is a specific but insensitive index of advanced asynergy.

Creatine Kinase↗

PubMed1975

Ischemia in aortic stenosis: hemodynamic prediction.

The records of 12 patients with aortic stenosis previously studied by Fallen et al. in 1967 before and after infusion of isoproterenol were reviewed to assess the value of hemodynamic indexes in predicting myocardial ischemia--defined as less than 5 percent transmyocardial lactate extraction or lactate production. Potential subendocardial blood supply was estimated from a diastolic pressure-time index (DPTI), calculated from the tension-time index (TTI). The ratio DPTI/TTI was used to estimate the supply/demand relation. Of eight patients with aortic stenosis but without associated coronary artery disease, four (Group A) metabolized lactate normally after administration of isoproterenol, and four (Group B) had biochemical evidence of ischemia. Three of four patients (Group C) with aortic stenosis and associated coronary artery disease had abnormal glycolysis after administration of isoproterenol. Calculated aortic valve areas were comparable in all groups. In patients with aortic stenosis alone, abnormal lactate metabolism occurred whenever DPTI/TTI was less than 0.30 (P smaller than 0.01) (Group B). Two of three patients with aortic stenosis and associated coronary artery disease (Group C) showed abnormal lactate metabolism when DPTI/TTI was greater than 0.6; this ratio was below 0.3 in the third patient. These results suggest that the supply/demand relation calculated from these readily obtained indexes may be useful (1) in predicting in which patients with aortic stenosis ischemia will develop, (2) in distinguishing the role played by associated coronary artery disease, and (3) as an adjunct to calculation of valve area since the quantitation of associated aortic regurgitation is not necessary.

Adult↗

PubMed1975

Abnormalities of left ventricular function and geometry in adults with an atrial septal defect. Ventriculographic, hemodynamic and echocardiographic studies.

Left ventricular function and motion in 12 adults with an ostium secundum atrial septal defect were analyzed utilizing biplane cineangiography. Values for left ventricular end-diastolic volume index, stroke volume index, ejection fraction, left ventricular end-diastolic pressure and mean rate of circumferential fiber shortening were compared with values in an age-matched group of 11 normal subjects. Comparisons of ventriculographic and echocardiographic data were also made in 5 patients and 10 control subjects. Cardiac index was smaller in patients than in the normal subjects (3.6 vs. 4.5 liters/min per m2, P less than 0.01). Although left ventricular end-diastolic pressure was similar (8 mm Hg in both groups), the end-diastolic volume index was significantly smaller in patients than in normal subjects (56 vs. 76 ml/m2, P less than 0.05). Stroke volume index was also significantly smaller in patients (40 vs. 52 ml/m2, P less than 0.01). The two groups had similar values for ejection fraction (65 +/- 2 percent [standard error of the mean] in patients vs. 68 +/- 2 percent in normal subjects), circumferential fiber shortening velocity (1.67 +/- 0.13 vs. 1.81 +/- 0.15 circumferences/sec.), heart rate (91 +/- 7 vs. 90 +/- 5 beats/min) and mean systemic arterial pressure (92 +/- 5 vs. 87 +/- 3 mm Hg). Early systolic bulging of the upper ventricular septum toward the right ventricle was seen in 10 of 12 patients with an atrial septal defect but in no normal subject. Echocardiographic data supported these findings. No other abnormalities of motion were consistently noted. It is concluded that the left ventricle of patients with an atrial septal defect is subnormal in volume and abnormal in sequence of contraction of the septum and is characterized by apparent decreased distensibility.

Adolescent↗

PubMed1975

The omnicardiogram: new approach to detection of heart disease in patients with a normal resting electrocardiogram.

The omnicardiogram is a new technique in which various leads of the standard electrocardiogram are digitized and subjected to a nonlinear mathematical transformation so as to detect subtle degrees of abnormality not apparent in the original electrocardiogram. Its usefulness in the detection of heart disease was studied in 121 male patients with a normal resting 12 lead electrocardiogram who underwent selective coronary cineangiography for a chest pain syndrome. In normotensive patients with a normal resting electrocardiogram, an abnormal omnicardiogram was recorded in 81 percent of those with three vessel disease, 67 percent of those with two vessel disease and 41 percent of those with one vessel disease. Nineteen percent of patients with normal coronary arteries or nonobstructive coronary artery disease had false positive tracings. The omnicardiogram was abnormal in 81 percent of patients with hypertension whether or not cornary artery disease was present. A double Master exercise test was performed by 109 of the 121 patients. In normotensive patients results of the test were positive in 67 percent of those with three vessel disease, 31 percent of those with two vessel disease and 14 percent of those with one vessel disease. There was a 4 percent rate of false positive tracings. Thus in our study, the omnicardiogram appeared to be superior to the Master test and to provide a useful new approach to detection of coronary artery disease in male patients with a normal resting electrocardiogram.

Coronary Angiography↗

PubMed1975

Echocardiographic analysis of mitral valve motion after acute myocardial infarction.

To examine the effects of acute myocardial infarction on mitral valve diastolic velocity, echocardiograms were performed in 18 patients on admission, daily in the Coronary Care Unit, and at 3-day intervals during the remainder of hospitalization. These patients were divided into three groups based on the time interval between onset of symptoms and initial echocardiogram. Five of six patients admitted within 5 hours of onset of myocardial infarction had a triphasic response of mitral valve diastolic velocity with a transient rise above initial values, followed by a fall to below initial values, and then a slow rise during recovery. Seven of eight patients admitted 1-2 days after onset of myocardial infarction had a biphasic response, i.e., a fall from initial values and then a slow rise. Four patients admitted later in the course of myocardial infarction had a monophasic response, i.e. low initial velocity followed by a slow recovery. We conclude that in patients with myocardial infarction the mitral valve diastolic velocity following myocardial infarction shows a triphasic response which may appear biphasic or monophasic depending on the interval between myocardial infarction and admission. The temporal pattern of mitral valve diastolic velocity changes may reflect the dynamic alterations of myocardial function and compliance that are occurring after acute myocardial infarction and during the recovery period.

Adult↗

PubMed1975

Relation between contractile reserve and prognosis in patients with coronary artery disease and a depressed ejection fraction.

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.

Cardiac Catheterization↗

PubMed1975

Vectorcardiographic diagnosis and electrocardiographic correlation in left ventricular asynergy due to coronary artery disease. I. Severe asynergy of the anterior and apical segments.

The transverse plane QRS loop vectorcardiogram (VCG) was analyzed in 102 consecutive patients, angiographically proven to have coronary artery disease (CAD), whose right anterior oblique left ventriculogram showed severe asynergy (akinesis or marked hypokinesis) of the anterior and apical segments. Eighty-four of the 102 loops were considered to be diagnostic of severe asynergy because similar loops were not found in patients with CAD with less severe asynergy of either or both segments or in normal control subjects. Eighty-two of the 84 showed a uniformly abnormal pattern. Posterior vectors exhibited partial or complete clockwise "rotation" and were much more prominent than early anterior forces. In fact, the latter were often absent. In the other two VCG's at least the early half of the loop displayed prominent anterior vectors. The ECGs showed marked variability of the QRS in leads V-2-V-6. Abnormal Q waves were present in only 63 of the 102. The numbers of these leads showing abnormal Q waves varied from one to all of these positions.

Bundle-Branch Block↗

PubMed1975

Ventricular function before and after direct revascularization surgery. A proposal for an index of vascularization to correlate angiographic and ventriculographic findings.

In order to determine the effect of direct bypass surgery on the total coronary arterial supply to the heart, a numerical construct was devised to incorporate the development of new obstructive lesions and the presence of patent or nonpatent grafts. This construct, termed a vascularization index (VI), was used to evaluate left ventricular function and anginal symptoms after coronary artery bypass surgery in 56 patients. Patients with an increase in local or total arterial blood supply (positive delts VI) often had similar directional changes in segmental wall motion and ventricular ejection fraction. Patients with a decrease in local or total arterial blood supply (negative delta VI), due to either nonpatent grafts or progression of atherosclerotic disease, also usually had similar directional changes in segmental wall motion and ventricular ejection fraction. (Although nearly all patients reported a decrease in anginal symptoms after surgery, delta VI could not identify degree of improvement.) Use of an integrated approach in describing pre and postoperative myocardial blood supply appears to be the most reliable method of explaining changes in left ventricular function.

Angiocardiography↗

PubMed1975

Main left coronary artery disease. Clinical experience from 1964-1974.

Obstructive lesions of the main left coronary artery (LCA) were demonstrated angiographically in 73 patients, comprising 4.3% of the total population referred to us for diagnostic evaluation of chest pain. Although there were no specific historical or clinical features which could absolutely distinguish this subgroup from the larger population of coronary artery disease patients, 81% (34/42) of the double Master's exercise tests, in which the patient achieved a heart rate of at least 110 beats/min. demonstrated greater than or equal 2 mm R-ST segmental depression. Of the total group of 73, 32 were evaluated during the six-year period from 1964 to 1971 and a preliminary report made in 1972. The diagnosis in the remaining 41 patients was established in the 1/2 year period from 1971 to 1973. The initial 32 patients were seen before the significance of a main LCA lesion was appreciated. In this subgroup there were five deaths at the time of cardiac catheterization. However, in the more recent group improved recognition of patients with possible main LCA disease prior to catheterization has led to a much lower death rate related to diagnostic catheterization. Only one of the last 41 patients undergoing coronary angiography has died. Nineteen patients were managed medically. Of this group 17 were considered to be under the same risk of death as the surgical candidates. Their mortality rate, as high. The risk of hying was 43.6% after 24 months, 51.1% after 36 months, and 73.6% after 42 months of observation. Although the initial surgical experience, using internal mammary artery implants and saphenous venin bypass grafts, was associated with a high mortality, direct revascularization surgery over the last 2 1/2 years has been accomplished with a perioperative mortality of only 6.2%. All deaths in the group of 40 patients receiving elective revasularization with saphenous vein bypass grafts occurred in the first six months following surgery. The risk of dying was 12.5% after six months of observation and was unchanged for the remainder of the follow-up period. After 21 months the difference in survival between the two groups is statistically significant (P less than 0.05). The one late death among the surgical survivors occurred four months after the operative procedure and was related to noncardiovaxcular surgical complications. The surgical survivors have been followed for an average of 27 months. Thus revascularization surgery has improved the prognosis for patients with main LCA disease. We currently advise prompt evaluation for any patient suspected of having this type of obstruction and urgent idrect revascularization surgery if this lesion is demonstrated angiographically.

Adult↗

PubMed1975

Prognosis in medically-treated coronary artery disease: influence of ejection fraction compared to other parameters.

The prognostic value of the left ventricular ejection fraction(EF) was compared to that of other commonly used indices--severity of coronary artery disease, left ventricular end-diastolic pressure, cardiac index, and abnormal ECG--in 144 patients with coronary artery disease followed for an average of 14 months on medical management. During this period, 14 patients (10%) died. Analysis of the mortality demonstrated that the EF was the most powerful predictor of short-term survival. Thus, patients with three-vessel coronary artery disease and anormal EF (greater than 0.50) had a significantly lower mortality (12%) than did patients with three-vessel CAD and a reduced EF (33%, P less than 0.001). Similar comparisons were observed within the subgroups with abnormal hemodynamics or an abnormal ECG. Therefore, the EF appears to be an important prognostic guide in the medical therapy of coronary artery disease, and is of significantly more discriminant value than other measurements when combined abnormalities exist.

Adult↗

PubMed1975

Right ventricular performance in patients with coronary artery disease.

While left ventricular (LV) performance in patients with coronary artery disease (CAD) has been extensively investigated, little attention has been given to right ventricular (RV) function in this disease. For this purpose, a new geometric model for RV volume has been developed and RV end-diastolic volume index (EDVI), end-systolic volume index (ESVI), stroke volume index (SVI) and ejection fraction (EF) have been determined from biplane RV cineangiograms in 26 patients. Eight patients served as normal (control) subjects (group I). Eighteen patients with obstructive CAD comprised two other groups: six who had no significant disease of the right coronary artery (RCA) (group II) and 12 who had a high grade RCA lesion (group III). The mean values for EDVI, SVI and EF in group I were 76 +/- 11 ml/m2, 50 +/- 6 ml/m2, and 66 +/- 6%. The only significant difference between groups I and II was that SVI was lower in group II than in group I (P less than 0.01). No measurements in groups II and III were statistically different from each other. However, markedly subnormal values were found in group III (EDVI: 61 +/- 16 ml/m2, SVI: 33 +/- ml/m2 and ef: 52 +/- 7%); all values being significantly lower (SVI and EF: P less than 0.001; EDVI: P less than 0.05) than in group I. RV end-diastolic pressure was normal in all patients. These findings may related to 1) reduced RV compliance, 2) distorted LV geometry, 31 possible RV ischemia or 4) reduced Frank-Starling effect.

Adult↗

PubMed1975

Detection of latent function in acutely ischemic myocardium in the dog: comparison of pharmacologic inotropic stimulation and postextrasystolic potentiation.

In poorly perfused myocardium with resultant ischemic dysfunction, augmentation of contractility can, under certain conditions, be used to detect viable but ordinarily noncontracting muscle. Two methods of inotropic augmentation, pharmacologic inotropic stimulation and postextrasystolic potentiation (PESP), were studied in acutely ischemic canine myocardium with controlled coronary blood flow. A caliper length gauge to record segmental shortening and left ventricle pressure was used to construct pressure-length loops. Acute regional ischemia depressed segmental function: early segmental shortening decreased (-20 plus or minus 0.02% [SE]) and frequent dyskinesia occurred. Restoring coronary blood flow corrected segmental shortening to control levels. During acute regional ischemia, PESP consistently augmented segmental function (+49 plus or minus 0.03%) and abolished dyskinesia. Pharmacologic inotropic stimulation with isoproterenol or calcium administered into the coronary arteries did not produce a comparable improvement in segmental function (+9 plus or minus 0.05%). Although early shortening markedly increased with pharmacologic stimulation, there was no consistent change in total shortening, and the area of the pressure-length loop decreased. Due to late dyskinesia, there was a decrease in injection shortening. Systemically administered pharmacologic agents accentuated early dyskinesia but caused no consistent change in total shortening. Unlike PESP, pharmacologic agents either worsened segmental function or caused responses that were minimum and inconsistent; such responses clearly cannot be used to identify viable ischemic myocardium.

Acute Disease↗

PubMed1974