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Biomedical subjects

A D Goldberg

Publications and source records attributed to A D Goldberg.

14 recordsLinked to original sources
PubMed1992

Spontaneous and inducible ventricular arrhythmias in a canine model of chronic heart failure: relation to haemodynamics and sympathoadrenergic activation.

The relationship between the incidence, frequency and complexity of spontaneous ventricular arrhythmias and the extent of haemodynamic compromise and sympathoadrenergic hyperactivity was evaluated in a canine model of chronic heart failure produced by multiple sequential intracoronary microembolizations. Ambulatory ECG Holter monitoring recorded during chronic heart failure in 18 dogs revealed spontaneous ventricular arrhythmias ranging from single ventricular premature beats (VPBs) to non-sustained episodes of ventricular tachycardia (VT). Single VPBs were present in 94% of dogs, couplets in 67%, triplets in 28% and spontaneous episodes of non-sustained VT in 33%. Dogs with > 28 VPBs.h-1 (n = 9) had a markedly higher plasma norepinephrine (PNE) concentration (1001 +/- 185 vs 561 +/- 31 pg.ml-1) (P < 0.03), and a higher pulmonary artery wedge pressure (PAWP) (18 +/- 2 vs 12 +/- 1 mmHg) (P < 0.03) than dogs with < or = 28 VPBs.h-1 (n = 9). Dogs that developed spontaneous episodes of VT also had significantly higher PNE levels (1119 +/- 247 pg.ml-1) compared to dogs that did not develop VT (612 +/- 64 pg.ml-1) (P < 0.02). Programmed ventricular stimulation performed in seven of 18 dogs resulted in the development of sustained monomorphic VT in three and ventricular fibrillation in three dogs each (43%, 43%). Dogs with inducible sustained monomorphic VT had a significantly higher number of ambient arrhythmias and higher PAWP compared to dogs that did not develop sustained VT. The observed complexity, frequency and incidence of spontaneous and inducible ventricular arrhythmias in this canine model are similar to those described in patients with chronic heart failure.

Animals↗
PubMed1978

Abnormalities of renal transport of sodium o-[131I]iodohippurate (Hippuran) in essential hypertension.

1. Renal function has been studied in 312 hypertensive patients by quantitative renography with sodium o-[131I]iodohippurate (131I-labelled Hippuran) and estimation of overall effective renal plasma flow. In 59% of the patients the results were normal. 2. Severe hypertension was associated not only with reduced effective renal plasma flow but also a characteristic abnormality of Hippuran transport in 10% of the patients in which there was a wider than normal variation in transit times of Hippuran through the kidney, which may reflect non-uniformity of reabsorption of filtrate by different groups of nephrons. 3. Plasma renin activity was higher in a group of 14 patients with multimodal transit time spectra than in a matched hypertensive control group, with very substantial overlap between the two groups. 4. The renographic abnormality was usually reversed by treatment.

Blood Flow Velocity↗
PubMed1978

Study of untreated hypertensive subjects by means of continuous intra-arterial blood pressure recordings.

Continuous recording of intra-arterial blood pressure and electrocardiograms has been performed in 41 ambulant untreated essential hypertensive subjects for periods up to 48 hours. Statistical analysis of the results has revealed: (1) A group of patients who developed a persistent tachycardia during the day. This response was not observed in a control population free of overt cardiovascular disease. (2) Three different haemodynamic responses to day-time activities suggesting different mechanisms for the production of high blood pressures. No normal controls are available for these changes. (3) No differences in responses between patients defined as 'labile' and 'fixed' hypertensives.

Adult↗
PubMed1977

Blood pressure and heart rate and withdrawal of antihypertensive drugs.

The immediate effects on heart rate and blood pressure of withdrawing antihypertensive drugs were studied over three-day periods in 26 patients. Four groups of drugs were studied. After withdrawal all patients taking clonidine showed a considerable increase in heart rate and blood pressure with intense ectopic activity. Patients taking postganglionic neurone-blocking drugs showed a similar but less pronounced reaction with increased ventricular ectopic activity. No alarming reactions were seen after withdrawal of methyldopa or beta-blocking drugs. Methyldopa and, especially, beta-blocking drugs are less likely to produce withdrawal reactions than clonidine or the postganglionic neurone-blocking drugs, and patients taking these drugs are therefore less likely to suffer violent reactions if they forget to take their tablets.

Adrenergic beta-Antagonists↗
PubMed1976

Patterns of blood-pressure during chronic administration of postganglionic sympathetic blocking drugs for hypertension.

Continuous recording of intra-arterial blood pressure in 11 ambulant patients taking postganglionic blocking drugs for the treatment of hypertension has shown an alternating pattern of high pressures at rest and very low pressures associated with exertion during normal daily activities. In 4 patients there was evidence of decreased cerebral or myocardial blood-flow during hypotensive episodes. It is suggested that these agents may predispose towards cerebral and myocardial infarction.

Adult↗
PubMed1975

Ambulatory electrocardiographic records in patients with transient cerebral attacks or palpitation.

Continuous electrocardiographic (ECG) records were made over 24 hours in 130 ambulant outpatients complaining of syncope, dizzy turns, or palpitation. In all these patients resting ECGs had failed to show significant dysrhythmias. Exercise testing was performed on 64 patients and also failed to reveal any dysrhythmias. Analysis of the tape recordings, however, showed appreciable dysrhythmias in 74% of the group. In most cases the dysrhythmias were complex mixtures of rapid supraventricular and ventricular rhythms. bouts of ventricular tachycardia were seen in seven patients, all of whom were women. Episodic complete heart block was seen in only two patients, but prolonged ventricular gaps (greater than 1-5 s), not associated with ectopic beats, were found in 26. No episodes of ventricular fibrillation were recorded. We conclude that many patients with vague symptoms suggestive of transient cerebral ischaemia or irregular heart action have significant and often dangerous dysrhythmias which can be diagnosed only by long-term recording of the ECG under fully ambulant conditions.

Adolescent↗
PubMed1975

Myocardial blood flow following saphenous vein bypass surgery.

Myocardial blood flow was measured by the 133Xe clearance technique in 21 patients 6 to 31 months after saphenous vein grafting for coronary arterial disease. Preoperative measurements were made in 16. All patients had improved symptomatically, and 20 had returned to work. Thirty of 39 grafts were entered and selective injections of 133Xe performed. Flow in the left coronary artery (LCA) was unchanged postoperatively in 9, increased in 5, and decreased in 1 (preoperative mean = 54 ml/100 g/min, SD +/- 16; postoperative mean = 65 ml/100 g/min, SD +/- 20). Flow in the right coronary artery (RCA) was unchanged postoperatively in 3, decreased in 9, and increased in 2 (preoperative mean = 46 ml/100 g/min, SD +/- 18; postoperative mean = 33 ml/100 g/min, SD +/- 12). Nine of 14 grafts to the left anterior descending coronary artery showed flow rates significantly greater than those in the corresponding LCA. Two of the 3 circumflex grafts showed flow rates significantly lower than those in the LCA. Four of 8 right grafts showed significantly higher flow rates than those in the corresponding RCA. These findings correlated well with the angiographic appearances. We conclude that saphenous vein grafting increases total myocardial blood flow. The data suggest that the coronary arteries and the grafts are supplying different regions of the myocardium, and that the graft regions were previously underperfused. There would appear to be little mixing of blood between artery and graft regions.

Coronary Artery Bypass↗
PubMedDate not supplied

Natural history and predictors of obesity after orthotopic heart transplantation.

Excessive weight gain resulting in obesity is commonly seen after orthotopic heart transplantation. Obesity increases the risk for the development of many significant health problems and the associated morbidity and mortality. The purpose of this study was to define the occurrence, magnitude, and predictors of overweight/obesity in this group. We followed 47 consecutive patients for 1 year after orthotopic heart transplantation for changes in weight. Weight gain from baseline was significant at months 2, 4, 6, 8, and 10, with significant weight increments between each measurement interval (p < 0.05). The mean weight gain was 10.1 kg +/- 1.6 (standard error [SE]) at 12 months. Based on entry body mass index patients were divided into two groups: group I, overweight/obese, body mass index more than 27 kg/m2 (n = 11); group II, not overweight/obese, body mass index 27 kg/m2 or less (n = 36). No significant difference was found in the amount of weight gained between the two groups (group I, 10.3 kg +/- 1.2 [SE]; group II, 10.1 kg +/- 1.4 [SE]). Only age predicted weight gain, with younger patients gaining more than older patients after transplantation (14.2 +/- 13.2 kg versus 8.8 +/- 7.9 kg; p < 0.05). We found no relationship between the observed weight gain and any of the other measured predictors, that is, history of overweight, age, diabetes, family history of overweight, sex, patient's participation in cardiac rehabilitation. The universal nature of this weight gain and the lack of markers predicting patients at greatest risk for obesity underscores the seriousness of this problem.

Age Factors↗