AV Shunt: a rare cause of cardiac decompensation]

HISTORY AND PHYSICAL EXAMINATION: A 66-year-old man presented with signs of heart failure for the first time. Apart from a history of arterial hypertension for several years, no relevant disease was known so far. The initial physical examination revealed symptoms of right heart failure and an elevated systolic blood pressure. INVESTIGATIONS: X-ray of the chest showed an enlarged heart shadow and no definite signs of pulmonary congestion. Echocardiography revealed a dilated left ventricle (left ventricular end-diastolic diameter 59 mm) with moderately reduced contractility (ejection fraction 35%). Laboratory parameters were normal. An invasive investigation of the reduced contractility was prepared. DIAGNOSIS, THERAPY, AND COURSE: While measuring blood pressure, a murmur and a little scar in the left elbow flexure were discovered. The suspicion of a traumatic arteriovenous fistula after a mirror glass injury 8 years ago was confirmed by sono- and angiography. The shunt volume was calculated by oxymetry as 6.2 l/min. The fistula was surgically dissected and ligated. At follow-up 1 year later, the patient reported no complaints and showed good exercise capacity. Echocardiography revealed normal parameters. CONCLUSION: This case demonstrates the reversibility of high-output heart failure after treatment of the underlying cause. It stresses the importance of careful interrogation and examination of the patient. Apparently obvious causal connections must be thoroughly worked up and critically questionned.     

Acute acral ischemia in all fingers possibly due to a Borrelia infection

Acute interruption of circulation in the distal fingers can be both expression of an embolic event as well as the first manifestation of a vasculitis or collagenosis. The search for its cause is frequently difficult. In many cases a specialized analysis of the coagulation system as well as diagnostics such as ultrasound scan of the heart or a systematic antibody scanning do not reveal the origin of an embolus or the underlying disorder. On the basis of a case-report we would like to focus on a possible context between an infection of Borrelias stage III and consecutive deterioration of peripheral arterial perfusion in the fingers. Besides Jo-1- and positive sceleton-muscle-antibodies there were no serological and clinical indications for an autoimmune disease. It was possible to avoid acral necrosis by means of an antibiotic, immunosuppressive and rheological therapeutic concept. We recommend to control the borellia-antibody-level in cases of obscure threatening peripheral necrosis caused by arterial perfusion stop.     

No association between transmembrane protein-tyrosine phosphatase receptor type C (CD45) exon A point mutation (77C>G) and idiopathic dilated cardiomyopathy

To investigate whether a 77C>G polymorphism in exon A of the CD45 gene causing a variant CD45RA expression pattern is associated with the development of idiopathic dilated cardiomyopathy (DCM), we studied a total of 414 individuals (104 patients and 310 controls). CD45RA expression pattern on lymphocytes was examined by flow cytometric analysis and subsequently the CD45 77C>G polymorphism was genotyped by polymerase chain reaction-allele specific restriction enzyme analysis (PCR-ASRA). We found 5 patients and 8 control individuals displaying the variant CD45RA expression pattern. All identified individuals carried the heterozygous CD45 77C>G polymorphism. The frequency of the 77G allele in the patient group was 2.4%, which was not significantly different from 1.3% found in the control group (p=0.327). In conclusion, the data of this preliminary study could not reveal any association between the CD45 77C>G polymorphism and susceptibility to idiopathic DCM in a German population.     

Reversibility of coronary endothelial vasomotor dysfunction in idiopathic dilated cardiomyopathy: acute effects of vitamin C.

In patients with idiopathic dilated cardiomyopathy, endothelium vasomotor function is disturbed. Increased oxidative stress and the consecutive formation of oxygen free radicals have been implicated as one possibility for this observation, suggesting that nitric oxide (NO) is inactivated by oxygen free radicals. We tested the hypothesis that the antioxidant, vitamin C, may improve endothelial function in idiopathic dilated cardiomyopathy. In 11 patients, the endothelium-dependent vasomotor response of the left anterior descending coronary artery to intracoronary acetylcholine (ACh) infusion (1/2 x 10(-6) mol/L, 1/4 x 10(-5) mol/L; respectively) was determined before and immediately after intravenous infusion of 3 g of vitamin C. Coronary cross-sectional diameter was obtained by quantitative coronary angiography, average peak velocity was measured by an intracoronary Doppler flow wire, and coronary blood flow (CBF) was calculated. Maximum cross-sectional diameter was determined after administration of nitroglycerin. Dose-dependent ACh showed a decrease in cross-sectional diameter (-5% to -7%, p <0.05) and an increase in average peak velocity (+16% to +25%, p <0.05); the CBF was unchanged (+1% to -2%, p = NS). After vitamin C infusion, the cross-sectional diameter increased in a dose-dependent manner from +11% to +15%, the average peak velocity increased from +20% to + 41% (p <0.05), and the CBF increased from +38% to + 82% (p <0.01, p <0.001, respectively). Thus, patients with idiopathic dilated cardiomyopathy had endothelial dysfunction, and administration of vitamin C reversed endothelium-dependent dysfunction.     

Transoesophageal left ventricular pacing in heart failure patients with permanent right ventricular pacing.

BACKGROUND: Previous studies of biventricular (BV) pacing for treatment of heart failure (HF) patients with left bundle branch block (LBBB) evaluated responders to BV pacing with acute transvenous left ventricular (LV) pacing and arterial pulse pressure (PP). The aim of this study was to assess transoesophageal LV pacing in evaluation of the haemodynamic response with a view to upgrading responders from permanent right ventricular (RV) pacing to BV pacing. METHODS AND RESULTS: Ten HF patients (age 62+/-8 years; one female, nine males) in NYHA III, LV ejection fraction 24+/-9% and permanent RV pacing by means of an implanted pacemaker or ICD were tested using transoesophageal LV pacing and PP. Permanently RV-paced HF patients were analysed with transoesophageal atrial sensed LV pacing in VAT mode with a different AV delay (n = 6) and with transoesophageal LV pacing in V00 mode during atrial fibrillation (n = 4). In five responders, PP was higher during transoesophageal LV pacing than PP during RV pacing (74+/-42 versus 57+/-31 mmHg, P = 0.015). Responders were upgraded by means of an LV lead via the coronary sinus in the posterior (n = 1) or posterolateral (n = 4) walls and after attaining a high LV pacing threshold with an epicardial LV lead on the anterior (n = 1) or anterolateral (n = 1) walls. NYHA class improved from 3 to 2+/-0.3 (P = 0.003) during 204+/-120 days follow-up and cardiac output increased from 4.4+/-1.5 to 5.6+/-1.7 l/min (P = 0.027) when comparing BV pacing and optimal AV delay with RV pacing. In five nonresponders, PP was not higher during transoesophageal LV pacing than during RV pacing. CONCLUSION: Transoesophageal LV pacing may be a useful technique to detect responders to BV pacing in permanently RV-paced HF patients.     

Direct coronary stent implantation without predilatation--a new therapeutic approach with a special balloon catheter design

Stent implantation serves as the gold standard for proximal lesions of the coronary arteries with a diameter between 2.75-3.5 mm. Our new concept aims at a reduced procedure duration and fluoro-time as well as a decreased ischemic period during stent implantation. A new therapeutic concept of a direct stent implantation without predilatation was tested using a specially developed balloon catheter on which various 14-16 mm long "slotted-tube" stents are mounted between two conical, radiopaque markers. In 105 consecutive patients, who were scheduled for angioplasty, this method of direct stent implantation was performed. Six of the procedures were performed for acute myocardial infarction and 8 in so-called high-risk procedures. The direct stent implantation was successful in 88%. In 6%, predilatation of the lesion site was necessary before stent placement. In the remaining 6%, a stent could not be successfully implanted despite the availability of various other systems. Comparison of the direct stent implantation with conventional stent placement with predilatation revealed that 1) The fluoro-time for direct stent implantation, compared to the conventional method, was 8.4 +/- 4.9 min vs. 13.7 +/- 8.0 min; p < 0.05, respectively. Furthermore, there were less balloons used per lesion for direct stent implantation (1.4 +/- 0.4) compared to the conventional method (1.7 +/- 0.7), but there was not a significant difference. 2) If we compare those patients with successful direct stent implantation with those with the unsuccessful procedures, the latter group had a higher percent of angiographically visible calcification at the site of the lesion (80% vs. 18%; p < 0.01). In addition, these patients had an increased average age (72 +/- 7 vs. 61 +/- 11 yrs; p < 0.01). The success rate of direct stent implantation did not depend on lesion diameter stenosis before PTCA. Stent dislocation was observed in 3.8% of the procedures, and a single case of stent embolism was seen. In conclusion, the direct stent implantation offers the advantages of a shortened fluoro-time, the use of fewer balloons, and has the potential of less ischemic stress compared to the conventional method of stent implantation with predilatation, if old patients with calcified lesions are excluded. This should be proved on a large scale in future studies also considering a learning curve with regard to the new method. Whether this new approach also reduces the restenosis rate, warrants further studies.     

Reproducibility of HTS-SQUID magnetocardiography in an unshielded clinical environment.

A new technology has been developed which measures the magnetic field of the human heart (magnetocardiogram, MCG) by using high temperature superconducting (HTS) sensors. These sensors can be operated at the temperature of liquid nitrogen without electromagnetic shielding. We tested the reproducibility of HTS-MCG measurements in healthy volunteers. Unshielded HTS-MCG measurements were performed in 18 healthy volunteers in left precordial position in two separate sessions in a clinical environment. The heart cycles of 10 min were averaged, smoothed, the baselines were adjusted, and the data were standardized to the respective areas under the curves (AUC) of the absolute values of the QRST amplitudes. The QRS complexes and the ST-T intervals were used to assess the reproducibility of the two measurements. Ratios (R(QRS), R(STT)) were calculated by dividing the AUC of the first measurement by the ones of the second measurement. The linear correlation coefficients (CORR(QRS), CORR(STT)) of the time intervals of the two measurements were calculated, too. The HTS-MCG signal was completely concealed by the high noise level in the raw data. The averaging and smoothing algorithms unmasked the QRS complex and the ST segment. A high reproducibility was found for the QRS complex (R(QRS)=1.2+/-0.3, CORR(QRS)=0.96+/-0.06). Similarly to the shape of the ECG it was characterized by three bends, the Q, R, and S waves. In the ST-T interval, the reproducibility was considerably lower (R(STT)=0.9+/-0.2, CORR(STT)=0.66+/-0.28). In contrast to the shape of the ECG, a baseline deflection after the T wave which may belong to U wave activity was found in a number of volunteers. HTS-MCG devices can be operated in a clinical environment without shielding. Whereas the reproducibility was found to be high for the depolarization interval, it was considerably lower for the ST segment and for the T wave. Therefore, before clinically applying HTS-MCG systems to the detection of repolarization abnormalities in acute coronary syndromes, further technical development of the systems is necessary to improve the signal-to-noise ratio.