The impact of automatic threshold tracking on pulse generator longevity in patients with different chronic stimulation thresholds.

Automatic adjustment of the stimulation output of pacemakers to changing stimulation thresholds using the Autocapture feature increases patient safety and decreases energy consumption. This study examined the impact of Autocapture on pulse generator longevity in patients with different chronic stimulation thresholds. Eighty patients (mean age 79 +/- 9 years; 37 men, 43 women) with Pacesetter Regency SR+ pacemakers were included in the study. Data were collected before discharge of the patients from the hospital, 6-12 weeks postimplant, and then every 6-12 months. Pulse generator longevity was calculated theoretically, assuming 100% stimulation with a stable threshold, at a pacing rate of 65 +/- 6 beats/min and 1% backup pulses. Theoretical pulse generator longevity was calculated for low (< 1 V), intermediate (> or = 1 V and < 2 V), and high (> or = 2 V) stimulation thresholds. Pulse generator longevity was compared among three groups: (A) Autocapture programmed On, (B) Autocapture programmed Off, (C) theoretical calculations using thresholds of patients in group A with the stimulation voltage programmed at twice pacing threshold, or at a minimum of 2.4 V. The mean follow-up time since implantation was 19 +/- 8 months. The calculated longevity benefits for patients in group A were 36%, 59%, and 30% compared to group B, and 19%, 32%, and 49% compared to group C in patients with low, intermediate, and high chronic stimulation thresholds, respectively. Theoretical calculations based on chronic stimulation thresholds in our patient population with Regency SR+ pacemakers suggest that Autocapture may markedly prolong pulse generator longevity in patients with a broad range of long-term pacing thresholds.

[Cocaine: its possible role in coronary arteriosclerosis and myocardial infarct. Case reports and review of the literature]. / Kokain: Seine möglichen Beziehungen zur Koronarsklerose und zum Herzinfarkt. Fallbeschreibungen und Literaturübersicht.

Cocaine is a frequently used drug with many known effects on the cardiovascular system. It leads also to structural changes of the coronary arteries that can result in severe chest pain or even acute myocardial infarction. We discuss two patients with infarction, differentiate between chest pain and infarction and suggest some important therapeutic measures.

[Balloon valvuloplasty of a discrete subvalvular aortic stenosis]. / Ballonvalvuloplastie einer diskreten subvalvulären Aortenstenose.

We describe the successful percutaneous balloon valvuloplasty of a discrete subaortic stenosis in an adult patient. The maximal gradient of 160 mm Hg (mean 100) was reduced to 45 and 33 mm Hg respectively. The procedure required only one overnight hospital stay.

[Transesophageal echocardiography in the diagnosis of endocarditis]. / Die transösophageale Echokardiographie in der Endokarditisdiagnostik.

Transesophageal echocardiography is a new diagnostic method for visualization of retrocardial structures and heart valves with high resolution. This retrospective analysis describes the use of and the findings by transesophageal echocardiography in patients suspected to suffer from endocarditis studied in three hospitals. 50 patients were studied; the diagnosis was confirmed in 64%, whereas 36% (controls) had other findings. The leading initial symptoms were fever and valvular incompetence. Laboratory parameters were altered in both groups with equal frequency. One or more diagnostic features were detected by transesophageal echocardiography in 88% of patients with endocarditis: vegetations (approximately with equal frequency on the mitral and the aortic, rarely on the tricuspid valve) were detected in 75% and/or abscesses in 22% of them. Only one patient in the control group with a history of endocarditis had vegetation-like structures on the aortic valve. Transesophageal echocardiography was on the average performed on the seventh day of hospitalization. With the exception of one female patient, all had been treated with antibiotics. Valve replacement was recommended in 65% of the patients with endocarditis and was in 59% also performed (single or double valve replacement), most frequently because of aortic or mitral regurgitation. The other patients were treated with antibiotics. Transesophageal echocardiography thus detects vegetations and abscesses in endocarditis frequently, findings that influence treatment in a significant manner.

[Transesophageal echocardiography: indications and findings. Experiences from 3 centers]. / Die transösophageale Echokardiographie: Indikationen und Befunde. Erfahrungen aus 3 Zentren.

The introduction of transoesophageal echocardiography has greatly enhanced the noninvasive diagnostic possibilities in cardiology. This multicentre report analyses the findings in different indications as well as the rate of complications in 335 consecutive patients on whom transoesophageal echocardiography was performed. The most frequent indication was the search for a cardiac source of embolism (36%). Compared to patients with other indications, thrombi in the left atrial appendage, atrial septal aneurysms and protruding aortic atheromas were significantly more frequent in this group. Transoesophageal echocardiography was performed in 20% for the diagnosis of suspected endocarditis and vegetations and/or paravalvular abscesses could be demonstrated in 46% of these patients. Other important indications included the assessment of mitral valve disease, congenital heart disease, valve prosthesis dysfunction and aortic dissection. Clinically relevant complications occurred in 1.8% and were spontaneously reversible in all cases. Transoesophageal echocardiography is an extremely valuable and safe diagnostic tool in cardiology.

The Omnicarbon tilting-disc heart valve prosthesis. A clinical and Doppler echocardiographic follow-up.

From 1986 to 1990, 172 patients with a median age of 60.5 years (range 20 to 79 years) received 187 Omnicarbon valves (109 aortic valve replacements, 48 mitral valve replacements, and 15 double valve replacements). Patients were followed-up for a median observation period of 2.5 years (range 4 months to 5.2 years) by clinical and Doppler echocardiographic examination. Follow-up was complete in 98%. Operative mortality (death within 30 days) was 1.7%, and linearized late mortality was 2.6% per patient-year, corresponding to an actuarial survival rate for operative survivors of 89% after 4 years. The overall 4-year postoperative survival was 87% (93% for aortic valve replacement, 77% for mitral valve replacement). Compared with age- and sex-adjusted Swiss death rates, there was an excess mortality of 5% after 4 years. Percentages for freedom from valve-related complications at 4 years are as follows: thromboembolism, 98% (aortic valve replacement, 98%, and mitral valve replacement, 96%); anticoagulant-related hemorrhage, 95%; valve endocarditis, 96%; reoperation, 96%; and permanent valve-related impairment, 99%. The overall 4-year event-free survival was 76% (80% for aortic valve replacement and 69% for mitral valve replacement). New York Heart Association class improved in 88% of the patients by 1 to 3 grades, and only 3% remained in class III after operation. For the most commonly used aortic valve (23 mm), Doppler echocardiography revealed a peak pressure gradient of 29 +/- 10 mm Hg, a fractional shortening/peak pressure gradient ratio of 1.34 +/- 0.61, and a performance index of 0.35 +/- 0.08. In the most commonly used mitral valve (27 mm), the mean pressure gradient was 4.0 +/- 2.1 mm Hg. We conclude that excellent clinical and hemodynamic results can be obtained with the Omnicarbon prosthesis, in both the aortic and mitral positions.

Recurrent bleeding after variceal hemorrhage: predictive value of portal venous duplex sonography.

OBJECTIVE: Risk assessment of recurrent variceal bleeding is essential for therapeutic decisions and is usually performed by endoscopy of the upper gastrointestinal tract. We studied the value of portal venous duplex sonography in predicting subsequent variceal bleeding in patients with cirrhosis. SUBJECTS AND METHODS: Thirty patients with cirrhosis who received sclerotherapy because of acute variceal hemorrhage for the first time (hemorrhage group), 30 patients with cirrhosis who had no previous hemorrhage (nonhemorrhage group), and 30 control subjects were examined prospectively. With the use of portal duplex and color Doppler sonography, flow direction, flow velocity, vein diameter, and response to respiration of portal vein vessels were measured and portosystemic collaterals and thrombosis of portal vessels were visualized. The results of these measurements and imaging findings were combined into a Doppler sonoscore. At entry into the study, all patients were classified on the basis of a sonoscore as having a low (sonoscore, < 4) or a high (sonoscore, > or = 4) risk for subsequent hemorrhage. During a mean follow-up period of 2 years (range, 15-36 months), the predictive value of this Doppler sonoscore was studied. RESULTS: In the hemorrhage group, the prevalence of recurrent hemorrhage was 40%, despite sclerotherapy, and the mortality rate was 60%. In patients with a Doppler sonoscore of 4 or more, the prevalence of recurrent hemorrhage was 67%, whereas in patients with a score less than 4, the prevalence was only 22% (p < .02). After sclerotherapy, endoscopic criteria showed no significant correlation with the prevalence of bleeding. In the nonhemorrhage group, the prevalence of variceal hemorrhage occurring was 13%, and Doppler sonographic criteria showed no significant correlation with the prevalence of subsequent hemorrhage. CONCLUSION: We conclude that Doppler sonography, performed after the first occurrence of variceal hemorrhage, provides useful prognostic information regarding the risk of recurrent hemorrhage. If these results are confirmed, Doppler sonography may be used to select the best method of treatment.

Aortic and mitral valve disease in patients with end stage renal failure on long-term haemodialysis.

OBJECTIVE: To identify valvar heart disease in patients with chronic uraemia by conventional and colour coded Doppler echocardiography. DESIGN: Case series of an unselected group of 62 patients with end stage renal failure. SETTING: Centre for haemodialysis in a referral hospital in Switzerland. PATIENTS: 62 patients on chronic haemodialysis. MAIN OUTCOME MEASURES: Frequency of structural and functional valve abnormalities and their relation to clinical findings. RESULTS: Structural changes were seen in 40 (64%) of 62 patients after 50 months (range 3-178 months) on haemodialysis. The mitral annulus and aortic cusps were thickened in 25 (40%) and in 34 (55%) patients respectively. Aortic stenosis was present in eight (mean (SD) age 60.5 (8.5) years), with a maximal instantaneous pressure gradient of 41 (14) mm Hg. Aortic regurgitation was seen in eight, mitral regurgitation in seven, and mitral stenosis in three patients. Patients with aortic stenosis had been on haemodialysis for significantly longer than the remaining patients (101 (43) v 46 (43) months, p = 0.01) and had significantly higher concentrations of serum alkaline phosphatase (176 (89) v 117 (47) IU/l, p less than 0.01) and of parathyroid hormone (54 (66) v 19 (29) ng/ml, p less than 0.02). CONCLUSIONS: Patients on long-term haemodialysis had an increased frequency of haemodynamically relevant changes in the aortic and mitral valves. The degenerative valve disease may be related in part to the duration of haemodialysis and to alterations in calcium metabolism as indicated by increased plasma concentrations of alkaline phosphatase and parathyroid hormone.

Influence of long-term amelioration of anemia and blood pressure control on left ventricular hypertrophy in hemodialyzed patients.

The course of left ventricular hypertrophy was investigated in anemic hemodialysis patients treated with recombinant human erythropoietin (r-huEPO). 12 patients, aged 60.8 +/- 9.9 years (mean +/- SD) were treated for 18.8 +/- 2.7 months. Left ventricular size was estimated by echocardiography performed before treatment and at least 12 months after relieving anemia. Patients had signs of left ventricular and/or asymmetric septal hypertrophy when compared with a nonanemic and normotensive control group matched for sex and age. At baseline, hemoglobin (Hb) was 8.6 +/- 0.7 g/dl; interventricular septum thickness (IVST) was 1.75 +/- 0.34 cm, left ventricular posterior wall thickness (LVPWT) 1.32 +/- 0.19 cm, left ventricular muscle mass index (LVMI) 222.7 +/- 41 g/m2 and blood pressure (BP) 146.4 +/- 10/81.6 +/- 6 mm Hg. Hb rose to 11.4 +/- 1.2 g/dl (p less than 0.001); IVST and LVMI decreased to 1.42 +/- 0.35 cm (p less than 0.02) and 155.4 +/- 25.1 g/m2 (p less than 0.001); LVPWT and BP remained unchanged (1.30 +/- 0.26 cm and 146.8 +/- 16.9/81.2 +/- 7.8 mm Hg) at the end of the study. During the observation period, two groups of 5 and 7 patients differed from each other. The group of 5 patients had higher BP values (158.9 +/- 9.8/86.5 +/- 5.3 vs. 140.0 +/- 9.5/79.2 +/- 6.8 mm Hg, p less than 0.01), and the period with Hb values above 10 g/dl was shorter (14.5 +/- 2.4 vs. 17.8 +/- 2.4 months, p less than 0.05). These 5 patients failed to show a significant decrease in IVST and LVMI.(ABSTRACT TRUNCATED AT 250 WORDS)

[Ambulatory transesophageal echocardiography. Diagnostic possibilities of a novel study method]. / Ambulante transösophageale Echokardiographie. Diagnostische Möglichkeiten einer neuen Untersuchungsmethode.

Transesophageal echocardiography has become now a routine outpatient method to augment the diagnostic power of transthoracic echocardiography in 10-15 minutes. Indications are native and prosthetic valvular heart disease and congenital heart disease, the evaluation of embolic events and suspicion of aortic dissection.

[Acute myocardial infarct following chemotherapy for testicular carcinoma: on the coronary toxicity of cytostatic agents]. / Akuter Myokardinfarkt nach Chemotherapie bei Hodenkarzinom: zur koronaren Toxizität der Zytostatika.

Two young patients who had been treated with cisplatin and bleomycin for testicular cancer developed acute myocardial infarction. 8 additional cases of premature myocardial infarction following chemotherapy for testicular cancer have been reported in the literature. The infarctions occurred several months or years after chemotherapy while most patients were in complete remission and had no significant risk factors for coronary artery disease. However, the pathogenesis of the assumed coronary toxicity associated with antineoplastic agents, usually with cisplatin and bleomycin, is not well understood; lesions of the endothelium with obstructive coronary fibrosis as well as disorders of the clotting system and coronary vasospasm have been considered as possibilities. We conclude that in patients treated for testicular cancer, special attention should be paid to symptoms suggestive of coronary artery disease.

[Echocardiography in emergency medicine: tool or toy?]. / Echokardiographie in der Notfallmedizin: Werkzeug oder Spielzeug?

In cardiovascular emergency medicine echocardiography allows in many patients a quick and gentle bedside examination. In particular in patients with acute arterial hypotension, suspected or known acute coronary heart disease and its complications and in patients with acute heart failure due to valvular heart disease a valuable narrowing down of the differential diagnosis can be achieved by the use of echocardiography. However, the use of echocardiography in acutely ill patients demands highly skilled investigators to avoid potentially dangerous errors. The echocardiographic examination in intensive or emergency care patients represents an invaluable diagnostic tool today and becomes a toy only in inexperienced hands.

Tricuspid valve endocarditis in the drug addict: a reconstructive approach ("vegetectomy").

This report describes the case of a 24-year-old female heroin addict with large tricuspid valve vegetation, recurrent septic pulmonary emboli, and renal failure, due to immune-complex nephritis. The clinical course was initially complicated by acute hepatitis A. Because of recurrent emboli and persistent fever despite adequate antibiotic therapy she underwent excision of the vegetation ("vegetectomy") and tricuspid valvuloplasty. She was well at follow-up 12 months later with trivial tricuspid regurgitation shown by doppler-echocardiography. Kidney and liver function were normal. Right-heart endocarditis in drug addiction and therapeutic approaches are discussed. In selected cases "vegetectomy" and valvuloplasty offer a promising therapeutic alternative.

[Transesophageal echocardiography]. / Transösophageale Echokardiographie.

Transesophageal echocardiography is a new, semi-invasive technique for the examination of the heart and the aorta. Within 10-15 minutes it is possible to obtain good pictures of the anatomy and function of the heart. Diagnostic indications are native and prosthetic valvular heart disease; the method is particularly suitable for visualization of endocarditic vegetations, evaluation of embolic events or congenital heart disease and assessment of aortic dissection. In the intensive care unit transesophageal echocardiography is a new window to the heart, yielding instantaneous information on cardiac status. For the anesthetist it is the first method to provide perioperative beat to beat analysis of ventricular function.

Emergency valve replacement for active infective endocarditis.

During the last 12 years, 14 patients were subjected to emergency heart valve replacement in acute bacterial endocarditis. Operative mortality was 21% (3/14); significant postoperative periprosthetic regurgitation or reinfection occurred in none of the survivors. Risk factors with unfavourable prognosis are: (1) virulent pathogens ("Non-Viridans"-germs); (2) previously normal heart valves; (3) acute aortic insufficiency with premature closure of the mitral valve; (4) floating vegetations shown by echocardiography. Our results provide further evidence for the efficacy of early surgical intervention in patients with bacterial endocarditis with an unfavourable etiology or a complicated course.