Regional and global left ventricular function during intra-aortic balloon counterpulsation in patients with acute myocardial infarction shock

We evaluated the improvement in hemodynamic and left ventricular (LV) function in 15 patients with acute myocardial infarction and cardiogenic shock, who were treated with intraaortic balloon counterpulsation (IABP). They were studied by flow-directed right heart catheterization and nuclear angiography. IABP decreased LV end-diastolic volume from 134 to 114 ml and LV end-systolic volume from 100 to 72 ml. LV stroke volume increased from 34 to 42 ml and cardiac output from 3.0 to 3.6 L/min. Global LV ejection fraction increased from 27.6% to 36.1%, and this was due to improvement in regional ejection fraction in ischemic areas. Pulmonary capillary wedge pressure and pulmonary blood volume decreased. Right ventricular ejection fraction also increased significantly. IABP improved LV function in acute myocardial infarction.     

Isovolumic relaxation period in man

Isovolumic relaxation period (IRP) was measured noninvasively from the onset of the aortic component of the second heart sound on the phonocardiogram to the point of separation of the mitral leaflets on the echocardiogram. IRP was measured in 83 patients: 10 normal subjects and 73 patients with different cardiac diseases.The duration of IRP was 58 ± 11 msec. in normal subjects. It was prolonged in hypertension (p < 0.001), HOCM (p < 0.001), aortic stenosis (p < 0.05), and aortic incompetence (p < 0.01), and was shortened in congestive cardiomyopathy (p < 0.05) and mitral stenosis (p < 0.01). In patients with coronary artery disease and normal over-all systolic LV function, IRP was prolonged (p < 0.001); IRP was shortened in four patients with coronary disease who had severe LV dysfunction and severe additional mitral incompetence.IRP was related to systemic blood pressure, percentage shortening of the LV in systole, and to the mitral EF slope. It tended to increase with increasing heart rate and a regression equation was developed for predicting IRP in relation to blood pressure and heart rate in normal subjects. There was no relation to the PR-AC time or to isovolumic contraction time. IRP is a useful measurement of LV dynamics in early diastole.     

Echocardiographic diagnosis of pulmonary atresia with intact ventricular septum.

The echocardiographic features of pulmonary valvar atresia with intact ventricular septum are described. The pulmonary valve fails to open during systole: there is a large pre-systolic 'a' wave dip, but the pulmonary valve membrane then returns to its closed diastolic position where it remains for the remainder of the cardiac cycle. The echocardiogram also provides valuable information about right ventricular size, the tricuspid valve, and aorta-mitral and aorta-septal relations.     

Improvement in regional ventricular function after percutaneous transluminal coronary angioplasty

We performed atrial pacing and radionuclide ventriculography in 12 patients before and after percutaneous transluminal coronary angioplasty (PTCA). Successful dilatation was achieved in 9 patients while in 3 the procedure was unsuccessful. Atrial pacing before PTCA showed ischemic dysfunction of the region supplied by the narrowed coronary artery. Regional ejection fraction decreased by 36 +/- 12% during rapid atrial pacing, while global left ventricular ejection fraction fell by 11 +/- 7% with a secondary increase in end-diastolic and end-systolic ventricular volume with the onset of ischemia. After successful PTCA, ischemic dysfunction was ameliorated or abolished. Measurements made at identical heart rates showed that both global and in particular regional left ventricular ejection fraction were significantly higher after successful angioplasty and did not fall during the stress of atrial pacing. There was no improvement in regional or global LV function in patients in whom angioplasty was not successful. The study showed that nuclear ventriculography with the stress of graded atrial pacing was a useful method for analysing the immediate results of coronary angioplasty and for studying its effects on regional myocardial function.     

Regional left ventricular ejection fraction from real-time two-dimensional echocardiography

We studied regional left ventricular contraction patterns and ejection fraction from real-time two-dimensional echocardiograms in 8 normal subjects, 11 patients with coronary artery disease and 2 with congestive cardiomyopathy. The ventricle was divided into 12 regions and for each region, we calculated ejection fraction using a method which integrated the incremental volumes of a series of hemicylinders constructed within that region. The data obtained were displayed graphically to provide a detailed picture of regional ventricular function. Normal subjects had a uniform regional ventricular pattern (regional ejection fraction 54–74%). In patients with coronary disease, we found varying degrees of regional ventricular contraction abnormalities. In congestive cardiomyopathy global hypokinesis was present, and regional ejection fraction was reduced in all areas (11–39%). The study showed that two-dimensional echocardiography is a useful non-invasive bedside technique which may provide detailed quantitative information relating to regional left ventricular contraction abnormalities.     

Echocardiographic LV function in thyrotoxicosis.

Serial echocardiographic studies were made in 11 patients with thyrotoxicosis. In the untreated thyrotoxic state heart rate was increased (96 ± 14 (SD) beats/minute) as were measurements of left ventricular (LV) contractility. LV shortening fraction was 40 ± 6 per cent (mean ± SD), mean velocity of circumferential fiber shortening was 1.60 ± 0.32 circumferences/sec., and velocity of posterior wall motion 71 ± 13 mm./sec. Stroke index and cardiac index were increased: 52 ± 18 (SD) ml./beat per M.² and 5.0 ± 1.8 (SD) liter/minute per M.², respectively. Cardiac chamber size was normal in all but one very ill patient and did not change during the study. Treatment with propranolol, 60 mg./day, produced a dramatic and immediate improvement in the clinical state of the patient. Heart rate decreased to 84 ± 11 beats/minute (p < 0.01), stroke index increased marginally (p > 0.05), and cardiac index was unaltered (p > 0.05). There was no change in parameters of LV contractility (p > 0.05). Treatment with a specific antithyroid drug (methimazole or propylthiouracil) brought about further improvement in the clinical state and a further decrease in heart rate (p < 0.01). LV contractility decreased and after two to three months, when the patients were euthyroid, these measurements were in the range of normal (per cent shortening of the LV diameter 37 ± 4, p < 0.01; mean velocity of circumferential fiber shortening 1.31 ± 0.23 circumferences/sec., p < 0.05; maximum velocity of posterior wall motion, 46 ± 14 mm./sec., p < 0.01). Systolic time interval measurements were in keeping with these data. They showed enhanced LV performance in the control state, no change with propranolol, and they returned toward the range of normal after definitive antithyroid treatment.     

Evaluation of the beta-blocking drug acebutolol in angina pectoris.

The effects of the beta-adernergic blocking drug acebutolol were studied in 23 patients with angina pectoris and angiographically documented coronary artery disease. Patients were evaluated clinically, by graded treadmill testing and by 24-hour Holter monitoring in the control state, after 2 weeks treatment with placebo, and after 2 weeks treatment with 600 mg. and then 1,200 mg. of acebutolol. Acebutolol (in a daily dose of 600 mg.) was an effective antianginal drug: the number of clinical attacks of angina pectoris (p less than 0.001) and the consumption of sublingual nitrate decreased (p less than 0.01), there was a significant increase in the treadmill effort tolerance as measured by the time to appearance of ischemic ECG changes (p less than 0.001) and the total work performed (p less than 0.001), and there was also a significant decrease in ischemic ST segment depression on 24-hour Holter monitoring. Treatment with 1,200 mg. acebutolol was associated with a further decrease in heart rate and a further improvement in effort tolerance on treadmill testing (p less than 0.05). On the large dose of the drug, however, there was no further clinical improvement, and no further improvement on 24-hour ECG monitoring; several patients complained of weakness and fatigue. Graded treadmill testing was an excellent objective method for assessing physical effort tolerance and its improvement after treatment with the beta-blocking drug. Twenty-four-hour Holter monitoring was a useful and complementary test, especially in patients who stopped exercising on the treadmill because of fatigue or weakness, and especially for assessing the efficacy of beta-blockade in controlling emotionally induced tachycardia and ischemia in the patient's own daily environment.     

The use of calcium with verapamil in the management of supraventricular tachyarrhythmias

Verapamil, a calcium channel blocking drug, terminates supraventricular arrhythmias but may have a negative inotropic effect and produce peripheral vasodilatation and hypotension. We studied the efficacy of intravenous calcium gluconate in reversing or preventing the hypotensive effect of verapamil in 31 patients with atrial tachyarrhythmias. In 21 instances, verapamil was given first, and in 13 calcium was used as pretreatment before the administration of verapamil. Calcium gluconate, when given as pretreatment, prevented the fall in blood pressure induced by verapamil, and when given after verapamil restored blood pressure to control values. The administration of calcium did not alter the antiarrhythmic effect of verapamil.     

Serum chromium in patients with recent and old myocardial infarction

The serum chromium in 45 subjects with no clinical evidence of ischemic heart disease was found to be 1.71 parts per billion (ppb) (S.E. ± 0.14). In 34 patients with a previously documented myocardial infarction, it was 1.84 ppb (S.E. ± 0.18). The difference was not significant nor was there any difference with age or sex. In 37 patients with acute myocardial infarction the serum chromium level rose to a mean of 6.36 ppb (S.E. ± 0.51; p < 0.001) during the first five days following the infarct, returning to normal over the next five days. There was no correlation between the serum chromium and blood glucose levels in these patients or in a further 14 patients who were receiving glucose infusions (chest pain without electrocardiographic or enzyme changes) or who were diabetics.     

Left ventricular function in beta-thalassemia and the effect of multiple transfusions.

Left ventricular performance was studied in 23 young patients with severe chronic anemia due to beta-thalassemia major and intermedia. The patients were divided into three groups according to the number of blood transfusions they had received. The left ventricle (LV) was enlarged in patients who had not received blood and larger still in patients who had received multiple transfusions. Echocardiography and systolic time interval measurements showed that systolic function of the LV was good in all the patients and that there was no statistical difference in systolic function in patients who had and those who had not received multiple transfusions. Heart rate was increased in the latter group. Stroke index and cardiac index were high, especially in patients in Group 3. The diastolic closure rate (EF slope) of the anterior mitral leaflet and its amplitude of movement were increased, but less so in Group 3; this may reflect an alteration in diastolic LV distensibility. The results indicate that despite the presence of cardiomegaly and severe clinical congestive heart failure, LV performance is well preserved in patients with beta-thalassemia, even in those who have received repeated blood transfusions. Clinical cardiac failure is the consequence of volume overload and abnormal chamber compliance. There was no evidence in this of a congestive cardiomyopathy.     

Relationship between extent of coronary artery disease and correlative risk factors.

An analysis was made of correlative factors which might be related to the angiographically measured extent of coronary artery disease in 140 patients. All patients presented with clinically important chest pain. Thirty-three had a normal coronary arteriogram. The extent of the atheromatous process was measured precisely at angiography by three different techniques. A coronary score, based on the percentage of luminal narrowing, was found to be best suited for the analysis. The most important contributory factors to the severity of atherosclerosis was duration of clinical history, number of previous myocardial infarctions, and male sex, but more specifically elevation of serum cholesterol and diabetes mellitus. Cigarette smoking, obesity, hypertension, a family history of atherosclerosis, and elevated serum triglycerides had a positive influence but this was not statistically significant.     

Chronic recurrent right ventricular tachycardia in patients without ischemic heart disease: Clinical,hemodynamic, and angiographic findings

Surgical cure of right ventricular tachycardia (RVT) has been recently described in patients with “arrhythmogenic right ventricular dysplasia,” a disease characterized by abnormal electrical activation of the right ventricle and localized or generalized angiographic right ventricular (RV) wall motion abnormalities (WMA). In search of a selective RV cardiomyopathy complicated by chronic recurrent RVT, 38 consecutive patients (mean age 30.5 ± 12 years) with RVT and no ischemic heart disease were studied clinically, noninvasively, and by cardiac catheterization including left and right ventriculography. RV volumes were as follow: end-systolic volume ranged from 23 to 103 (mean ± SD, 45.8 ± 20) cc/m² and was abnormal in 14 patients (37%); end-diastolic volume ranged from 57 to 138 (90.5 ± 26) cc/m² and was abnormal in 15 patients (39%); ejection fraction (EF) ranged from 0.18 to 0.64 and was decreased in five patients (13%). Seventeen patients (45%) had abnormal RV volume, EF, and/or pressures (RVD), five (13%) of whom had abnormal LV volume, EF, and/or pressures (LVD), and 12 (32%) patients with RVD had no LVD. Twenty-one patients (55%) had no RVD, two of whom had LVD. Only two of the 17 patients had RV regional WMA, one with and one without LVD. Most patients with LVD five of seven (71%) also had RVD while 12 of 31 patients (39%) with no LVD had RVD. In conclusion, less than one half of patients with RVT had selective RV cardiomyopathy and more than one half of patients with RVT had normal RV hemodynamics and angiography.     

P-wave analysis in myocardial infarction,pulmonary edema,and embolism

In a retrospective study, the P-terminal force in Lead V₁ (PTF-V₁) was measured in three groups, each of 35 patients, with the respective diagnoses of acute myocardial infarction without pulmonary edema, acute pulmonary embolism, and acute pulmonary edema. In all but one of the patients with acute pulmonary edema, a highly negative PTF-V₁ value was obtained, whereas by contrast, all the patients with pulmonary embolism had normal PTF-V₁ values. Four of the patients with acute myocardial infarction had abnormal PTF-V₁ values, although at the time there was no clinical or radiologic evidence of pulmonary edema. However, one of these patients did develop acute pulmonary edema a few hours later.Measurement of the PTF-V₁ is a simple noninvasive test that may, therefore, be useful in separating patients with acute pulmonary embolism from those with acute or impending pulmonary edema.     

In vivo atrial excitability and anti-arrhythmic drugs

The threshold of excitability of the atrial muscle was studied in the in vivo beating canine heart. Unipolar cathodal and anodal strength-interval curves were constructed and found to be dissimilar in shape. It was found that at any interval within the relative refractory period of the atrium, as in the ventricle, there is a wide range of current levels delineated by an upper (Tu) and lower (Tl) limit of threshold which can stimulate the atrial myocardium. Within these limits the threshold varies spontaneously and can be reduced to Tl level by a run of extrasystoles.Such Tu and Tl curves were repeatedly determined following administration of therapeutic doses of quinidine, procaine amide or lidocaine. It was observed that all three drugs prolonged the refractory period. The Tu values increased following each of the drugs, and mostly after quinidine, while the Tl curve was less affected by quinidine. It is suggested that the exit block thus produced is the principal mechanism whereby quinidine depresses atrial disrhythmias.