Experience using the Quinton Permcath for haemodialysis in the Irish Republic.

BACKGROUND: The Quinton Permcath has been widely used for temporary vascular access in patients requiring haemodialysis. Placement under direct vision into the internal jugular vein minimizes the complication rate. This access modality is being used more and more for long-term access in the elderly and in patients where other access modalities are unavailable or have failed. METHODS: We reviewed the results of 50 central venous Permcaths inserted under direct vision in 61 patients, over a 4-year period. The overall survival and complication rates are estimated. A detailed description of the catheter insertion and removal is provided. RESULTS: Seventy-six per cent of patients were successfully managed using the Permcath for a median duration of 105 days. In addition, nine patients (18%) had catheters functioning without complications for over 1 year. Twenty-six (42.6%) catheters were removed for complications. Seven patients had a single and two had second catheter reinsertion during the course of the study. CONCLUSIONS: The Quinton Permcath remains a reliable method for short-term vascular access. When other access modalities are unavailable, it may offer a valuable alternative for long-term haemodialysis.

Gastrinoma presenting as chronic pancreatitis.

We present here an unusual case of a pancreatic gastrinoma that caused recurrent episodes of clinical pancreatitis secondary to complete obstruction of the main pancreatic duct. The patient did not manifest signs or symptoms of peptic ulcer disease.

Usefulness of myocardial ischemia as predictor of training effect in cardiac rehabilitation after acute myocardial infarction or coronary artery bypass grafting.

Exercise capacity increases to a variable degree in coronary patients during cardiac rehabilitation. The effect of baseline exercise-induced ischemia on the response to a 12-week conditioning program was evaluated in 106 coronary patients. The magnitude of exercise conditioning response was greater in nonischemic patients than in ischemic patients, with maximal exercise intensity increasing 69 versus 50% (7.2 to 12.1 vs 7.1 to 10.6 METs) (p less than 0.05) and maximal oxygen consumption increasing 28 versus 10% (23.1 to 29.6 vs 23.0 to 25.4 cc/kg/min) (p less than 0.05). Markers of conditioning during submaximal exercise such as heart rate and heart rate-systolic blood pressure product were similarly reduced in both groups. The groups did not differ by age, diagnosis, resting ejection fraction, incidence of beta-blocker use, maximal exercise capacity, maximal exercise heart rate, blood pressure or intensity of actual exercise training. These results suggest that exercise-induced ischemia alters the stimulus to adapt to exercise training.

Effect of metoprolol on the submaximal stress test performed early after acute myocardial infarction.

To determine the effect of beta-adrenergic blockade on the submaximal stress test after acute myocardial infarction (AMI), 36 post-AMI patients performed their treadmill test on 2 separate days, with and without metoprolol, in a double-blind, placebo-controlled, crossover design study. Rest and peak submaximal exercise heart rate was diminished by 100 mg of metoprolol administered twice daily (from 84 +/- 3 to 68 +/- 2 beats/min, p less than 0.001, and from 126 +/- 3 to 97 +/- 2 beats/min, p less than 0.001, respectively) compared with placebo. Rest and peak submaximal systolic blood pressure was also decreased (from 121 +/- 3 to 108 +/- 2 mm Hg, p less than 0.001, and from 151 +/- 4 to 124 +/- 3 mm Hg, p less than 0.001). Exercise-induced ST-segment depression of 1 mm or more from baseline occurred in 12 patients taking placebo. However, only 4 of these patients had ST depression when they exercised while taking metoprolol (p less than 0.05). Angina pectoris occurred in 4 patients taking placebo but in only 1 of these taking a beta-blocking drug. It is concluded that beta-blocking therapy renders the post-AMI submaximal stress test less sensitive for markers of exercise-induced ischemia than if the test is performed without the drug. Therefore, when using the prognostic information of published studies, it is important to define the conditions surrounding the exercise test.

Exercise conditioning in the elderly coronary patient.

We compared conditioning effects of a supervised exercise program in 100 elderly and younger patients with a recent coronary event. Twenty-one patients were greater than or equal to 62 years of age (mean, 65 years) and 79 were less than or equal to 61 years of age (mean, 48.7 years). While the elderly patients attained a lower peak exercise intensity on entry and on completion of the exercise protocol, they obtained a similar relative training benefit as the younger patients. Peak exercise intensity increased 68% in each group and submaximal (five METS) heart rate-blood pressure product decreased 27% in the older patients and 26% in the younger patients. Rate of entry into our program was substantially lower in the elderly patient group, 19% v 57% in younger patients (P less than 0.001) despite a similar inhospital recruiting effort. Thus, although elderly coronary patients obtain similar training benefits as younger patients, they are less likely to participate in a program designed to decrease cardiac disability.

Comparative diagnostic value of exercise polarcardiography and 14-lead electrocardiography in the detection of coronary artery disease.

Early postexercise polarcardiographic (PCG) changes in the ST segment vector, as reflected in the variable MS X theta, are reported to clearly distinguish normal subjects from those with myocardial ischemia. We prospectively assessed the value of this test in detecting coronary artery disease (CAD) during treadmill exercise in 178 patients within 1 week of diagnostic coronary angiography. The average postexercise MS X theta was 16.9 +/- 9.7 mV degrees in patients with CAD, whereas it was 16.2 +/- 10.2 mV degrees in patients with CAD (p = NS). The optimal ratio of sensitivity to specificity, using different normal-abnormal cutoff values, was 57% and 56%, respectively, for a delineating MS X theta value of 12. The sensitivity and specificity of a simultaneously recorded 14-lead ECG using the criterion of exercise-induced horizontal downsloping ST segment depression greater than or equal to 0.1 mV, was 71% and 78%, respectively. The PCG results were not improved by analyzing MS X theta during exercise, or by analyzing the difference in MS X theta between rest and exercise or rest and postexercise. The sensitivity of the PCG for multivessel or left anterior descending CAD was higher than for less severe forms of CAD, but was significantly less sensitive than the 14-lead exercise ECG (70% versus 84%; p = 0.02; and 62% versus 75%; p = 0.05, respectively). Thus, exercise polarcardiography, as employed in the present study, does not improve the diagnostic content of the 14-lead exercise ECG. Contrary to previous reports, there is no clear separation of normal from abnormal MS X theta values when a prospective series of patients is tested.

The diagnosis and management of nausea and vomiting: a review.

Nausea and vomiting can result from a wide variety of organic and psychogenic disorders. In evaluating these symptoms, a thorough history with careful attention to their duration and relation to meals, as well as to concomitant drug use and underlying chronic medical problems, often will point to the correct diagnosis. A wide variety of diagnostic modalities exist, including radiographic studies, endoscopy, radionuclide methods of assessing gastrointestinal motility, and imaging studies of the central nervous system. These techniques must be used wisely and are not all required to elucidate the etiology in every patient. Treatment can be symptomatic but is directed at the underlying pathological process whenever possible. Recently developed gastrointestinal "prokinetic" agents have helped to improve the course of patients with identifiable motility disorders.

Propylthiouracil and hepatitis. Two cases and a review of the literature.

Propylthiouracil-induced hepatitis is an uncommon entity. Two further cases are reported herein, and the clinical and laboratory features of the other six cases in the English literature are reviewed. The initial appearance of the disease is similar to that of viral hepatitis, characterized by nausea, vomiting, and jaundice. The biochemical pattern of injury is predominantly hepatocellular, with marked elevation of transaminase valves and less striking elevation of alkaline phosphatase values. Recovery is usually complete after withdrawal of the drug, but there have been at least two fatalities, including the first patient (to our knowledge) whose case is reported herein. Despite its rarity, the disease should be suspected in any patient receiving propylthiouracil in whom clinical or laboratory evidence of hepatocellular injury develops.

Sixteen failures in a single model of bipolar polyurethane-insulated ventricular pacing lead: a 44-month experience.

During a 44-month period, 105 Medtronic model 6972-58 polyurethane-insulated, bipolar ventricular pacing leads were implanted, of which 16 failed clinically at a mean of 20.5 months post-implant. Pacing dysfunction presented as either intermittent or complete loss of sensing and/or capture and, rarely, oversensing . Thirteen of the 16 patients were asymptomatic, and problems were detected in 11 instances during routine telephonic surveillance. At the time of lead replacement, low or widely fluctuating lead resistance values and high current drain were uniformly observed. The single lead capable of total extraction revealed rupture of both internal and external insulation. A brief summary of the currently much-discussed "polyurethane controversy" is presented, and the issue of patient management is discussed.

Nine-year experience during 1973-1982 with 1,060 pacemakers in 805 patients.

Our experience with over one-thousand pacemaker implantations resulting in almost 28,000 patient pacing months is reviewed. Data are presented regarding changing indications for pacing, experience with numerous pacemaker types, patient survival, comparative mortality of sick sinus syndrome and complete heart block, and telephone surveillance. Consistent with some previous reports, there were high one- and two-year post-implant mortality rates, and advanced age at implant was associated with decreased survival. Males had a significantly higher mortality rate. The period reported covers the transition from utilization of mercury-zinc batteries to lithium power cells and other new technology; significant differences were observed in device reliability and patient mortality when comparing these eras. Certain patients evidenced disparate survivals, the most notable difference being seen in those who received their primary implants prior to 1976 and subsequent implants of more modern units.

Tuberculosis affecting a cadaveric renal allograft.

Tuberculosis is one of the more serious infections complicating renal transplantation. Although the incidence appears to be low, a dose of prednisone greater than 10 mg daily has been associated with a more severe form of disease. A case of tuberculosis with renal allograft involvement is described with documented bacteriological and radiological involvement in which treatment was successful with anti-tuberculosis chemotherapy. Deterioration in renal function did not occur. The prophylaxis of patients undergoing transplantation with a history of tuberculosis and the features, diagnosis and treatment of tuberculosis affecting a renal allograft are discussed.

Micro-processor synthesis and analysis of the polarcardiogram.

A low-cost micro-processor combined with a standard 3-channel electrocardiographic recorder was adapted to polar coordinate conversion of Frank orthogonal lead signals and display of the resultant polarcardiogram. The processor also functions as a computer of average transients for the ECG complexes and provides automatic recorder function at specified intervals during electrocardiographic exercise stress testing. Polarcardiographic variables such as magnitude, longitude and latitude at particular temporal points are calculated and values displayed by the micro-processor. The configuration provides an economical, accurate and reliable alternative to larger systems and may easily be adapted to other applications.

Comparative sensitivity and specificity of exercise electrocardiographic lead systems.

A comparison of current exercise electrocardiographic lead systems reveals differences in the sensitivity and specificity of S-T segment shifts diagnostic of obstructive coronary artery disease. The differences are explained in part by differences in population samples, lead systems and criteria for positivity. Multiple electrocardiographic lead recording in symptomatic patients during and after exercise improves sensitivity in detecting S-T segment shifts with only a small decrease in specificity. A review of population screening studies in asymptomatic subjects shows a wide selection of different exercise electrocardiographic lead systems and criteria for a positive test. Few screening studies have compared the prevalence of different S-T segment configurations in individual leads of a simultaneously recorded multiple lead system during or after exercise. Data from animal studies of myocardial ischemia suggest why 100 percent sensitivity in detecting obstructive coronary disease is unlikely to be obtained with surface electrocardiographic recordings. Additional research is required to identify the optimal set of diagnostic exercise electrocardiographic leads and criteria for positivity so that maximal predictive accuracy can be obtained for different patient subsets.

S-T segment elevation and coronary spasm in response to exercise.

The prevalence rate of exercise- S-T segment elevation of 0.1 mV or greater in symptomatic patients is 3.0 to 6.5 percent in most studies. S-T segment elevation is associated with a more severe degree of myocardial ischemia than depression and frequently implies a high grade coronary stenosis in the vessel that supplies the site of ischemia. Leads V4 to V6 and bipolar lead CM5 have been found to be relatively insensitive in detecting exercise-induced S-T segment elevation. The pathogenesis of S-T segment elevation is different in three clinical patient subsets reviewed. In patients afer infarction, the largest of the three subgroups, exercise-induced S-T segment elevation usually appears in leads with Q waves, is more common after anterior myocardial infarction and implies underlying akinetic of dyskinetic wall motion. Of patients with variant angina, 10 to 30 percent have during exercise S-T segment elevation that is most likely provoked by coronary arterial spasm. The natural history of variant angina is cyclic, and clinical observations and laboratory findings are dependent on particular phases in the disease process and treatment. Finally, 0.2 to 1.7 percent of symptomatic patients without infarction or variant angina have exercise-induced S-T segment elevation. Although most of the latter have fixed high grade coronary arterial stenoses at angiography, the exact pathogenetic mechanism of S-T segment shift in this patient group is not yet fully understood.