Recognition of myocardial infarction complicated by left anterior hemiblock: a diagnostic dilemma.

A patient with acute extensive anterior and old inferior wall myocardial infarction developed left anterior hemiblock, resulting in loss of the electrocardiographic evidence of infarction. While the vectorcardiogram has generally been found useful in diagnosing coexistent hemiblock and inferior myocardial infarction, serial vectorcardiographic studies failed to identify myocardial infarction masked by the development of left anterior hemiblock in this case. This report highlights the occasional diagnostic problem posed by the association of this conduction abnormality with myocardial infarction and emphasizes the need for careful evaluation of patients with history of chest pain and left anterior hemiblock on the electrocardiogram.

Protection of ischemic myocardium: comparison of effects of propranolol, bevantolol and N-dimethyl propranolol on infarct size following coronary artery occlusion in anesthetized dogs.

The relative extent of myocardial infarction produced by occlusion of the left anterior descendens coronary artery in anesthetized dogs was determined under control conditions or following treatment (4 h after ligation) with propranolol (1 mg/kg), bevantolol (3 mg/kg) or N-dimethyl propranolol (10 mg/kg). Doses of drugs were selected to provide similar reductions in heart rate, aortic blood pressure and contractility. Infarct size was estimated indirectly from levels of plasma creatine phosphokinase and measured histochemically by nitroblue tetrazolium stain.

Campylobacter enteritis and Yersinia enterocolitica infection in New Zealand.

A three-month survey was undertaken to determine the incidence of Campylobacter jejuni and Yersinia enterocolitica in diarrhoeal disease and acute abdominal disease in Palmerston North. C. jejuni was isolated from five domiciliary patients and one hospitalised patient with acute diarrhoea but there were no isolations from patients suffering from acute abdominal disease.

Mitral valve prolapse in the elderly.

This study included 40 patients over 60 years of age with echocardiographic findings of mitral valve prolapse (MVP). Most of these patients were unaware of any cardiac disorder until the time of echocardiography. In the majority, the clinical manifestations were benign, and the duration of symptoms variable.

The effect of an exercise program on change in curve in adolescents with minimal idiopathic scoliosis. A preliminary study.

Forty-two adolescents with minimal idiopathic scoliosis, who had been on an exercise program for 9 to 15 months, were evaluated to determine the influence of exercise on change in their curvatures. A difference of 4 degrees or greater between initial and final curve measurements was considered to be a change. Five percent of the curves increased, 74% remained the same, and 21% decreased.

A prospective study of mitral valvular prolapse in young men.

A cardiac history, a physical examination, an electrocardiogram, phonocardiograms in the supine and standing positions, and an M-mode echocardiogram were obtained in 100 randomly selected, presumably healthy, male medical students (mean age, 26 years). Four percent met standard echocardiographic criteria for mitral valvular prolapse. No midsystolic clicks or late systolic murmurs were appreciated in this group, and none complained of chest pain or palpitations.

The increasing isolation of Serratia species from clinical specimens.

A 14-month survey was undertaken in a diagnostic bacteriology laboratory to determine the incidence of Serratia spp. in routine clinical specimens. Gram-negative organisms with enterobacteria-like colonies were tested by a simple screening procedure.

Pericardial effusion and electrical alternans: echocardiographic assessment.

Clinical diagnosis of pericardial effusion is often difficult, and assessment of the effects of effusion on cardiac hemodynamics is often imprecise. Electrical alternans is a reasonably specific ECG indicator of the presence of a large effusion and imminent or actual cardiac tamponade. If echocardiography verifies the presennce of pericardial fluid and shows abnormal cardiac motion, a diagnosis of cardiac tamponade can be made without further, more invasive, studies.

Right ventricular performance during ischemia: an anatomic and hemodynamic analysis.

This study in the pig was designed to characterize right ventricular (RV) contractile responses during infarction involving three areas of the heart--anteroseptal, anterolateral, and inferoseptal. Porcine coronary architecture was studied from multicolor vinyl casts. Distribution of blood supply to ventricular myocardium and papillary muscles was defined by intra-arterial dye injection.

Spatial and nonspatial influences on the TG-ST segment deflection of ischemia. Theoretical and experimental analysis in the pig.

Spatial and nonspatial aspects of TQ-ST segment mapping were studied with the solid angle theorem and randomly coded data from 15,000 electrograms of 160 anterior descending artery occlusions each of 100-s duration performed in 18 pigs. Factors analyzed included electrode location, ischemic area and shape, wall thickness, and increases in plasma potassium (K(+)). Change from control in the TQ-ST recorded at 60 s (DeltaTQ-ST) was measured at 22 ischemic (IS) and nonischemic (NIS) epicardial sites overlying right (RV) and left (LV) ventricles.

TQ-ST segment mapping: critical review and analysis of current concepts.

Controversy and confusion surround many aspects of TQ-ST segment mapping today. Technical standards pertaining to the recording and measurement of the TQ-ST deflection have not been uniformly established nor has the correlative value of the deflection as an indicator of myocardial injury been clearly ascertained. The TQ-ST deflection is believed to originate primarily although not exclusively as a result of extracellular potassium accumulation in the ischemic region and subsequent establishment of a transmembrane potential gradient during diastole and systole at the ischemic boundary.

Early changes in contractility and coronary blood flow in the normal areas of the ischemic porcine heart.

The regional responses of normal myocardium distant from an ischemic area were studied during acute anterior descending occlusion in the open-chest chloralose-anesthetized pig. Three markers of regional response in both normal and ischemic areas were used: surface ECG electrode, a force gauge in series with left ventricular outer wall fibers, and coronary blood inflow to each region as determined by electromagnetic cuff-probes. Following brief anterior descending artery occlusion (120 sec).

The carriage of Escherichia coli on the peri-urethral area and in the feces in patients on long term low dose cotrimoxazole therapy.

Peri-urethral and fecal carriage of E. coli has been studied in 30 patients maintained on long term low dose cotrimoxazole and in abacteriuric subjects not receiving any antibiotic. Cotrimoxazole treatment is associated with a dramatic reduction in E.

The contribution of anticoagulants to platelet dysfunction with extracorporeal circulation.

This investigations evaluates the effects of anticoagulants on platelet function. Fresh human blood from 40 nonmedicated volunteers was anticoagulated with 4.3 units per milliliter heparin and/or acid-citrate-dextrose (ACD) solution 1:9.

Digital computer analysis of M-scan echocardiograms.

In the past few years, echocardiography has emerged as a useful noninvasive clinical tool in cardiac diagnosis. Conventional methods for analyzing echocardiographic data involve time consuming and tedious manual techniques for measuring various distances and computing cardiac parameters of interest. This paper describes a useful method for automating the analysis of M scan echocardiograms both for routine clinical work as well as for special research oriented ultrasonic cardiac studies.

The QRS complex during myocardial ischemia. An experimental analysis in the porcine heart.

Although ST segment deflections have been widely utilized as a means of assessing the degree of underlying ischemic injury, the relationship of QRS complex alterations to the ischemic process is poorly understood. In this study we made a beat-to-beat analysis of the QRS complex in terms of ventricular activation time (CT) and R wave voltage (V) in the acutely ischemic porcine myocardium and analyzed the relationship of these responses to changes in the area of ischemic involvement, altered myocardial energy demands, and plasma [K+]0 levels. With the onset of ischemia the QRS complex underwent a specific and reproducible biphasic sequence with an initial decrease in CT and V indicating a transient increase in the conduction velocity of the ischemic tissue.

Biventricular dynamics during quantitated anteroseptal infarction in the porcine heart.

The porcine heart has been shown to have close anatomic similarity to the human heart and was used as the experimental model in this study to gain further understanding of the early responses of both ventricles during acute anteroseptal myocardial infarction. High fidelity pressure and flow data were measured and multiple preejection and ejection variables were calculated for both ventricles. Infarct weight and distribution in both ventricles were quantitated.

Scoliosis: A prospective epidemiological study.

A two and a half-year prospective study was carried out to determine incidence rates and distributions of various parameters associated with idiopathic scoliosis. Data were also collected on the progression curves detected at the initial screening. The results showed: (1) that the incidence rate was 13.

Precordial and epicardial surface potentials during Myocardial ischemia in the pig. A theoretical and experimental analysis of the TQ and ST segments.

The solid angle theorem was used to analyze the relationships between TQ and ST segment deflections recorded from precordial and epicardial locations and the time course, size, shape, and transmural location of the ischemic process in the ventricular myocardium. Mathematical predictions were compared with experimental data from the intact heart. Precordial electrograms obtained in anesthetized close-chest pigs were compared with epicardial electrograms recorded directly from the heart's surface.