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Effective blood pressure control was associated with stable or improving renal function in nonblacks but not in blacks. These findings emphasize the importance of blood pressure control to maintain adequate renal function in hypertensive white men and raise important questions about the relationship of pressure reduction and renal function change in blacks.

Szmek B, Neuwirth R, Fiala M. Transaortální ablace incesantní komorové tachykardie po náhradě aortální chlopně mechanickou protézou. Cor Vasa 2010;52:643-645. V kasuistice prezentujeme případ mladé pacientky po náhradě aortální chlopně pro závažnou regurgitaci při infekční endokarditidě, u které byl pooperační průběh komplikován vznikem incesantní pravidelné tachykardie se štíhlým komplexem QRS. Pro přechodnou pooperační AV blokádu II. stupně, která neumožňovala nasazení antiarytmik, bylo provedeno elektrofyziologické vyšetření s nálezem komorového původu arytmie. Fokus ve výtokovém traktu levé komory v blízkosti Hisova svazku byl následně odstraněn radiofrekvenční ablací retrográdním přístupem přes mechanickou protézu. Klíčová slova: Aortální chlopeň -Mechanická náhrada -Komorová tachykardie -Katetrová ablace Szmek B, Neuwirth R, Fiala M. Transaortic ablation of incessant ventricular tachycardia after aortic valve replacement by a mechanical prosthesis. Cor Vasa 2010;52:643-645.We present the case of a young lady who underwent aortic valve replacement for serious regurgitation due to infectious endocarditis and in whom the postoperative course was complicated by incessant regular tachycardia with a narrow QRS complex. Because of a transient postoperative second-degree AV block, which precluded antiarrhythmic therapy commencement, she underwent an electrophysiological study demonstrating ventricular origin of the arrhythmia. The focal source in the left ventricular outfl ow tract was subsequently eliminated by radiofrequency ablation using the retrograde approach through the mechanical prosthesis.

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Utrecht, NetherlandsPurpose: Irreversible electroporation (IRE) creates deep and wide myocardial lesions, consisting of fibrosis after several weeks. There are no data on acute myocardial lesion development. We investigated early myocardial lesion development (first 60 minutes) created by IRE. Methods: In 7 pigs (+70 kg), with a custom linear suction device 4 single cathodal 200 Joule applications were randomly delivered at different epicardial RV sites, at 4 different 10-minute time intervals. A total of 7 sets of 4 myocardial lesions each (with lesion ages: 0; 10; 20; 30; 40; 50 and 60 minutes) were obtained during the first 60 minutes after IRE. Euthanasia was performed 60 minutes after the first IRE. Lesion characteristics were explored histologically. Results: Myocardial lesions resembled a necrosis pattern with interstitial edema and contraction band formation, immediately present after IRE. Hematoxylin-Eosin staining displayed interstitial edema (recognizable as empty space between cardiomyocytes, §) and contraction band formation (eosinophilic staining cross bands reflecting myocyte hypercontraction, #) ( Figure). Lesion demarcation could not be estimated histologically, because the main features of myocardial necrosis were not contiguously visible due to a variable muscular fiber direction in the cross-sections and irregular lesion margins with extensions. There was no further histological lesion development in the next hour. Adverse mechanical effects were not observed. Conclusion: Immediately after IRE, myocardial lesions were visible and histologically observable. They did not show further histological development in the next hour. Between 1993 and 2009, 2.9 million patients received permanent pacemakers in the United States, with over 600,000 new implants every year, establishing a great clinical need for pacing therapy. This work is aimed at generating an isolated atrial perfusion for easy access, higher throughput testing of novel atrial pacing or ablation technologies. Conflict of interest: none A NOVEL BENCH-TOP ISOLATED ATRIAL PREPARATION FOR TESTING ATRIAL PACING AND ABLATION TECHNOLOGIESIn this pilot study, swine hearts (n ¼ 4) and a portion of a human donor (n ¼ 1) heart (non-viable for transplant) were acquired. The specimens were transsectioned at the atrioventricular valve plane, isolating the atria intact. Each aorta was cannulated and perfused with an oxygenated Krebs-Henseleit buffer via a retrograde perfusion. The identified distal main branches of the left anterior descending and right coronary arteries were occluded to promote coronary perfusion in the atria. Prototype helical active fixation leads were fixed in the right atrial appendage to assess tissue viabilities; impedances, sensing thresholds, and pacing thresholds were then taken.The atrial preparations remained viable for pacing over the course of hours (swine: .240min and human 145min). The mean acute pacing thresholds were 1.75 + 0.13V in swine (n ¼ 32 placements) and 2.48 + .53V in human hearts (n ¼ 10 placements). Lead i...