G.Charles Oliver

Long-term prognosis after first Q-wave (transmural) or non-Q-wave (nontransmural) myocardial infarction: Analysis of 593 patients

Follow-up results in 593 patients less than or equal to 7 years (mean 4.7) after hospital discharge for their first myocardial infarction (MI) are presented. Patients were grouped according to the presence or absence of Q waves on electrocardiograms after the MI and by peak serum glutamic oxalacetic transaminase (SGOT) level during hospitalization. Cardiac mortality varied. Patients with Q-wave infarcts and an SGOT level less than or equal to 240 IU/liter had a cardiac mortality of 3.1% per year, whereas patients with Q-wave MI and an SGOT level greater than 240 IU/liter had an 11% 6-month mortality and a 3.8% per year cardiac mortality thereafter. However, patients with non-Q-wave (nontransmural) MI had a excellent survival rate for 2 years (96.8%) which continued in patients aged less than or equal to 60 years thereafter. However, patients with non-Q-wave infarcts aged greater than 60 years had a 12% per year cardiac mortality in the third post-MI year and an additional 12% died each year thereafter. Early mortality was related to enzyme level, whereas late mortality was a function of type (Q-wave or non-Q-wave) and age.

Radioimmunoassay for digoxin: Technic and clinical application

Abstract A rapid and sensitive radioimmunoassay for digoxin is described, which is capable of detecting as little as 25 μμg of digoxin. This assay, requiring as little as 0.1 ml of serum or urine, allows measurements of blood or urine digoxin concentration to be made easily within one working day. Patients judged on clinical grounds to have digoxin toxicity had average plasma digoxin levels of 3 mμg/ml. Patients thought to be adequately digitalized had average plasma levels of 1.6 mμg/ml, and those considered to be inadequately digitalized had average levels of 0.5 mμg/ml. These differences are highly significant (p

Recurrent Left Atrial Myxoma Report of a Case

Recurrence of a left atrial myxoma 6 years after the initial resection is reported. This, to our knowledge, is the second such case, and it emphasizes the need for a complete resection of the underlying atrial septum or atrial wall in cases of myxoma.

Detection of premature ventricular contractions with a clinical system for monitoring electrocardiographic rhythms

Abstract An evaluation was made of the performance of an on-line computer system for the detection of premature ventricular contractions. Following a rigidly defined protocol, 34 patients having an average PVC rate of almost one out of every twelve beats were studied, and approximately fifty thousand beats were analyzed independently by human observer and correlated with computer analysis. In the population studied, 78% of the PVCs were detected accurately. In addition, no patient was encountered having a PVC which was always missed by the computer. No false positive PVCs occurred in half the cases, and in 31 cases, only 39 computer labeled “PVCs” could be clearly called false positive PVCs based on information in the single-lead electrocardiogram. The patients studied had a variety of different rhythm complications including atrial fibrillation and premature ventricular contractions from multiple foci. The factors affecting performance were analyzed and directions for future improvement discussed.

Coupling interval and types of ventricular ectopic activity associated with ventricular runs

Repetitive 10-hour ECG recordings of 289 patients obtained within a year after myocardial infarction were analyzed for the presence of ventricular runs, and their association with various types of ventricular ectopic activity (VEA), average rate of premature ventricular complexes (PVCs), and coupling interval of PVCs initiating the runs. Tapes which contained complex VEA (bigeminy, multiform PVCs, couplets, or runs), early PVCs (coupling interval less than 400 msec), or late PVCs (coupling interval greater than 600 msec) had a substantially higher average PVC rate than those without them. The occurrence of ventricular runs was significantly more likely in tapes having other complex VEA or late PVCs than in those without them, and when tapes were stratified by PVC rates the presence of these dysrhythmias appeared to have an independent predictive value for the occurrence of runs. In contrast, the influence of early PVCs on the occurrence of runs was rather minimal, and this seemed to be related to their common association with the PVC rate. Furthermore, a larger percentage of isolated PVCs had coupling intervals between 400 msec and 600 msec, and most couplets (77%) and runs (67.8%) were initiated by PVCs with coupling intervals in this range. However, the proportion of either short (less than 400 msec) or long (greater than 600 msec) coupling interval PVCs initiating couplets or runs was significantly higher than those with intermediate coupling intervals (between 400 and 600 msec).

Absorption and Transport of Digitoxin in the Dog

Absorption of digitoxin as its studied in 14 fasted anesthetized dogs after administration of 50 μc of 3H-digitoxin mixed with 1 mg of unlabeled digitoxin into either the duodenum or stomach. Radioactivity was measured in portal, hepatic, and central venous plasma, thoracic duct lymph, common duct bile and urine for 5 hours after digitoxin was given. Three dogs were given a single intravenous dose of 25 μc of 3H-digitoxin mixed with 0.5 mg of unlabeled digitoxin, and radioactivity was measured in central venous plasma and thoracic duct lymph. Digitoxin was absorbed rapidly and uniformly from the duodenum and entered the body entirely by way of the portal vein, reaching peak concentrations in portal blood in 1 to 15 minutes. Digitoxin was absorbed erratically from the stomach. No metabolites of digitoxin were observed in selected portal venous samples subjected to thin-layer chromatography. Absorption of orally administered digitoxin into the systemic bloodstream is retarded because of highly efficient hepatic extraction of the drug and subsequent transfer into bile.

Compact digital storage of sequential left ventricular contours

Abstract A method is described that permits compact permanent storage of left ventricular (LV) contours in a minicomputer system. The method employs a “box encoding” algorithm first proposed by Freeman (1) to obtain a nearly eightfold reduction in the amount of information needed to store a left ventricular contour. Using this system, a ventricular contour can be stored in 100 computer words or less. The method is easy to implement, fast, allows variable data compression, and accurately reproduces the LV contour. In addition, the encoded contour lends itself readily to further computer processing.

Successful Operative Repair of Acyanotic Tetralogy of Fallot in a 61-Year-Old Man

Abstract A case of acyanotic tetralogy of Fallot—classic tetralogy anatomically with a predominant left-to-right shunt—that was repaired operatively in a 61-year-old man is reported. This represents, to our knowledge, the oldest reported patient with a tetralogy malformation to receive successful corrective surgery. The patients relatively mild pulmonic obstruction was probably the most significant factor in his long survival. Paradoxical embolization and progressive severe congestive heart failure were the main indications for operation.

Effects of Pharmacologic Agents on Human and Canine Pulmonary Veins

Abstract The effect of several pharmacologic agents on isolated human and canine pulmonary vein strips suspended from a force transducer was tested. Serotonin, norepinephrine and epinephrine caused contraction in most segments tested. Digitoxin was found to induce contraction of the pulmonary vein segments after a variable latent period. Tolazoline and aminophylline caused relaxation in a large number of the veins tested, although relaxation of human vein strips in response to tolazoline was less consistent. This study adds to the knowledge of the reactivity of human pulmonary veins.

Left ventricular pressure analysis: Design and validation of a computer algorithm with an investigation of inter-physician variability☆

Abstract Algorithms have been developed for the automatic determination of end-diastolic (EDP) and systolic (SYSP) pressures from left ventricular (LV) pressure waveforms acquired during cardiac catheterization. The algorithms were developed using two independent sets of LV waveforms designated the training set and the test set. Eight cardiologists independently analyzed each waveform in both the test and training sets. The training set data was repetitively processed by the computer. In each iteration algorithm parameters were adjusted to reduce the error between the computer analysis and the average of the eight physicians. When this process was completed, the validity of the final algorithms was verified by comparing computer and physician analysis of the test set data in a prospective manner. Interphysician variability (average standard deviation for all beats analyzed) for the test set was 1.47 mm Hg for EDP and 1.87 mm Hg for SYSP. The mean difference between automatically determined pressures and the average results of the eight physicians was 0.98 mm Hg for EDP and 0.97 mm Hg for SYSP. Automatically determined pressures were more accurate than pressures measured by all but one physician for SYSP and two physicians for EDP. The algorithm has been incorporated into a catheterization laboratory system and is in routine clinical use.