Recanalisation of coronary chronic total occlusions with new techniques including the retrograde approach via collaterals.

OBJECTIVE: Percutaneous treatment of coronary chronic total occlusions (CTO) remains one of the major challenges in interventional cardiology. The strategies of recanalisation in CTO have changed drastically due the development of new techniques such as the retrograde approach via collaterals. In this single-centre experience we sought to analyse the success rates with the use of different CTO techniques, the complication rates, and we evaluated predictors of failed CTO recanalisation attempts. METHODS AND RESULTS: In this single-centre observational study we analysed the prospectively entered data of 331 consecutive patients, undergoing percutaneous coronary intervention (PCI) for CTO in 338 lesions at the Heart Center Wuppertal between June 2007 and July 2010. Nineteen lesions were attempted twice and one lesion three times (=358 procedures). The lesion-related success rates were 81.1%. Single-wire usage was the predominant strategy used in 198 antegrade cases (65.6%) followed by parallel wire technique and see-saw technique in 94 cases (31.1%). In the retrograde procedures, the reverse CART technique was predominantly used (35.7%), followed by retrograde wire passage (17.9%), marker wire (17.9%) and CART (14.3%). The in-hospital complications were low and comparable with conventional PCI data. The presence of blunt stump, severe calcification, severe tortuosity and occlusion length >30 mm were independent predictors of procedural failure. CONCLUSIONS: A high degree of success with low in-hospital complications comparable with conventional PCI data can be expected in the hands of experienced CTO operators. A second try with a retrograde approach after antegrade failure should be considered.

Increased TNF-alpha and decreased TGF-beta expression in peripheral blood leukocytes after acute myocardial infarction.

Inflammation contributes to the development of atherosclerosis and cardiovascular events. Counteracting pro- and anti-inflammatory responses of serum cytokines have been reported, but the relevance of TNF-alpha, TGF-beta and IL-6 gene expression in peripheral blood leukocytes and their contribution to systemic inflammation in atherosclerosis, especially after acute myocardial infarction (AMI), has not been investigated yet. Using quantitative RT-PCR, we determined temporal cytokine mRNA expression alterations in blood cells from patients with AMI (n = 51). Serum cytokine concentrations were analyzed in parallel using the ELISA technique. TNF-alpha mRNA expression rates and serum concentrations were significantly elevated in AMI patients compared to controls (n = 77), while mRNA expression and serum content of TGF-beta were decreased. Interestingly, we found no statistically significant correlation between transcript and protein levels, indicating that gene expression in leukocytes may be an independent sign for systemic inflammation. While IL-6 was significantly increased in serum from AMI patients with positive correlation to left ventricular dysfunction and negative correlation to ejection fraction, IL-6 mRNA levels did not differ between patients and controls. Gene expression alterations indicate a sophisticated regulation of counteracting TNF-alpha and TGF-beta cytokine expression in peripheral blood leukocytes after AMI with bias towards a pro-inflammatory situation.

[Therapy options for Prinzmetal angina induced ventricular vulnerability]. / Therapieoptionen einer Prinzmetal-Angina induzierten ventrikulären Vulnerabilität.

We report about a 46 year old male, who survived sudden cardiac death caused by recurrent ventricular tachycardia as the clinical manifestation of a vasospastic right coronary artery. After implantation of an implantable cardioverter defibrillator, the patient did not respond to conservative treatment despite of different drug therapies. Therefore, the vasospastic right coronary artery was treated by a percutaneous transluminal coronary angioplasty and stenting, which could not reduce the occurrence of further tachycardias. Finally, the patient underwent an operative myocardial revascularization combined with sympathectomy. During the whole follow-up of six months no new episodes of ventricular tachyarrhythmias have occurred.

Echocardiographic quantification of regional left ventricular wall motion with color kinesis.

Echocardiographic assessment of regional systolic left ventricular function is usually performed qualitatively and depends on investigator experience. In this study, we investigated a new method for quantifying regional systolic wall motion based on color kinesis. In this study, regional systolic wall motion velocity (Vsys) was determined by dividing end-systolic color width by systolic time. High regional wall motion velocity (Vhigh) was determined by dividing the width of the widest color by its duration of 40 ms. First, in vitro measurements with an acrylic glass model were obtained; these demonstrated a high correlation between echocardiographically determined and real "wall motion velocities" (R = 0.99, p<0.001, R2 = 0.99). Then, 17 healthy, young persons were examined, and normal values for each left ventricular wall segment (16-segment model) were determined. The mean Vsys and Vhigh of all 272 wall segments were 2.3+/-0.6 and 7.4+/-1.8 cm/s, respectively. Finally, in 12 patients with coronary artery disease and prior myocardial infarction, Vsys and Vhigh of each left ventricular wall segment were determined and compared with conventional echocardiographic wall motion analysis using the usual 4-grade score system. Analysis of data showed that quantitative color kinesis measurements demonstrated significantly lower velocity values in pathologic than in normal wall segments (Mann-Whitney U test, p<0.05). Measurements discriminated between pathologic and normal wall motion, with an accuracy of 89% for Vsys and 83% for Vhigh (chi-square test, p<0.05). To summarize, in this first study, measurements of regional wall motion velocities with color kinesis demonstrated reliable results for the quantification of regional left ventricular systolic function.

Polarity reversal improves defibrillation efficacy in patients undergoing transvenous cardioverter defibrillator implantation with biphasic shocks.

The purpose of this study was to determine the influence of polarity reversal on DFT in patients undergoing implantation of nonthoracotomy defibrillators with biphasic shocks. Previous studies have shown higher defibrillation efficacy with using the distal electrode as anode implantation of nonthoracotomy defibrillators and monophasic shocks. However, it is as yet unclear whether biphasic shock defibrillation will also be influenced by polarity reversal. Using a transvenous lead system with a proximal electrode in the superior caval vein and a distal electrode in the RV apex, 27 patients undergoing defibrillator implantation were randomized to DFT testing "initial" (distal electrode = cathode) or "reversed" polarity (distal electrode = anode). Defibrillation energy was reduced stepwise until defibrillation failure occurred. At this point, polarity was switched and testing continued until the lowest energy requirement was determined for both polarities. With reversed polarity, DFT was 11.1 +/- 5.7 J versus 13.3 +/- 5.8 J with polarity (P = 0.033). This means a 17% reduction of the DFT. In 10 patients, the threshold was lower with reversed, whereas in 3 patients it was lower with initial polarity. In conclusion, changing electrode polarity in transvenous implantable defibrillators with biphasic shocks may significantly influence defibrillation energy requirements. Therefore, polarity reversal should always be attempted before considering patch implantation.

[Chronic frequency-adaptive pacemaker therapy in patients with heart failure]. / Chronische frequenzadaptive Schrittmachertherapie bei Patienten mit Herzinsuffizienz.

Twenty patients (complete AV block n = 13, sick sinus syndrome n = 4 (replacement of a VVI system), bradyarrhythmia n = 3) with rate-adaptive pacemakers (respiration volume guided n = 10, QT-driven n = 1, dual sensor (QT/activity) system n = 9) were randomly assessed by ergospirometry after 4 weeks of VVI- (70 bpm), VVIR1-(70-110 bpm, low upper rate) and VVIR2-pacing (70-130 bpm, high upper rate). Oxygen uptake (VO2), work load (W), and heart rate were determined at peak exercise (max) and at the anaerobic threshold (AT). In the whole population, rate adaptation led to a significantly higher VO2-max than VVI-pacing for both VVIR1- (15.5 +/- 5.1/12.6 +/- 4.1 ml/kg/min, 28 +/- 37%, p < 0.01) and VVIR2-pacing (14.8 +/- 4.4/12.6 +/- 4.1 ml/kg/min, 20 +/- 23%, p < 0.01). At the AT, however, VO2 was significantly improved only by the VVIR1 mode (low upper rate, 9.8 +/- 2.5/8.0 +/- 2.1 ml/kg/min, 28 +/- 36%, p < 0.01). Regarding only patients with moderately limited exercise capacities (Weber class C, n = 11), rate adaptive VVIR1 and VVIR2 pacing could not produce a significant increase of VO2-max and VO2-AT. In contrast, patients with severely reduced exercise capacities (Weber class D, n = 9) significantly profited from the rate adaptation, but only in the VVIR1 mode (VO2-max 48 +/- 45%, VO2-AT 51 +/- 38%, p < 0.01). Thus, in the whole population an increase of oxygen uptake and of exercise workload at the anaerobic threshold could only be achieved by pacing with the low upper rate of 110 bpm. By this, particularly patients with heart failure and a severely limited exercise tolerance (Weber D) had a significant benefit. Therefore, the upper rate should be programmed in a lower range in patients with heart failure, at least for rate-adaptive ventricular pacemaker systems.

[High-frequency current ablation of a Mahaim fiber at the tricuspid annulus]. / Hochfrequenzstromablation einer Mahaim-Faser am Trikuspidalklappenring.

The Mahaim syndrome is a rare variant of accessory pathways. Typically, a normal surface ECG and paroxysmal tachycardias with left bundle branch block morphology are found. The anatomic correlate is an atrioventricular or atriofascicular fiber with decremental conduction properties. Criteria for intracardiac mapping of the atrial insertion of such a fiber include: 1) maximal preexcitation and a short stimulus-QRS interval with differential pacing from the atrial aspect of the tricuspid annulus, and 2) recording of an accessory pathway potential ("M" potential). We report a case of a patient that underwent successful radiofrequency ablation of a Mahaim fiber at the tricuspid annulus.

Potential of intracardiac ultrasonography as an adjunct for mapping and ablation.

Radio frequency catheter ablation of cardiac tissues has evolved rapidly as the standard therapy for various arrhythmias. Current mapping techniques include fluoroscopy and endocardial ECG recordings. These techniques are time-consuming and give only limited information with regard to cardiac anatomy and pathology. Moreover, fluoroscopy leads to significant radiation exposure to the patient and the operator. Intracardiac ultrasonography is a promising new technique that may improve intracardiac anatomic orientation, reduce radiation exposure, allow better control of lesion formation during radio frequency current application, and identify possible complications such as thrombus formation or perforation. Intracardiac ultrasonography systems that are presently available are limited by insufficient penetration depth and image resolution. Technical refinements are discussed that may improve the applicability of intracardiac echocardiography for electrophysiologic mapping procedures.