Bentall procedure 39 years after implantation of a Starr-Edwards Aortic Caged- Ball-Valve Prosthesis

We report a case of a male patient who received an implantation of a Starr-Edwards-caged-ball-valve-prosthesis in 1967. The surgery and postoperative course were without complications and the patient recovered well after the operation. For the next four decades, the patient remained asymptomatic - no restrictions on his lifestyle and without any complications. In 2006, 39 years after the initial operation, we performed a Bentall-Procedure to treat an aortic ascendens aneurysm with diameters of 6.0 × 6.5 cm: we explanted the old Starr-Edwards-aortic-caged-ball-valve-prosthesis and replaced the ascending aorta with a 29 mm St.Jude Medical aortic-valve-composite-graft and re-implanted the coronary arteries

Diastolic dysfunction and arrhythmias caused by overexpression of CaMKIIδC can be reversed by inhibition of late Na+ current

Transgenic (TG) Ca2+/calmodulin-dependent protein kinase II (CaMKII) δC mice develop systolic heart failure (HF). CaMKII regulates intracellular Ca2+ handling proteins as well as sarcolemmal Na+ channels. We hypothesized that CaMKII also contributes to diastolic dysfunction and arrhythmias via augmentation of the late Na+ current (late INa) in early HF (8-week-old TG mice). Echocardiography revealed severe diastolic dysfunction in addition to decreased systolic ejection fraction. Premature arrhythmogenic contractions (PACs) in isolated isometrically twitching papillary muscles only occurred in TG preparations (5 vs. 0, P < 0.05) which could be completely terminated when treated with the late INa inhibitor ranolazine (Ran, 5 μmol/L). Force–frequency relationships revealed significantly reduced twitch force amplitudes in TG papillary muscles. Most importantly, diastolic tension increased with raising frequencies to a greater extent in TG papillary muscles compared to WT specimen (at 10 Hz: 3.7 ± 0.4 vs. 2.5 ± 0.3 mN/mm2; P < 0.05). Addition of Ran improved diastolic dysfunction to 2.1 ± 0.2 mN/mm2 (at 10 Hz; P < 0.05) without negative inotropic effects. Mechanistically, the late INa was markedly elevated in myocytes isolated from TG mice and could be completely reversed by Ran. In conclusion, our results show for the first time that TG CaMKIIδC overexpression induces diastolic dysfunction and arrhythmogenic triggers possibly via an enhanced late INa. Inhibition of elevated late INa had beneficial effects on arrhythmias as well as diastolic function in papillary muscles from CaMKIIδC TG mice. Thus, late INa inhibition appears to be a promising option for diastolic dysfunction and arrhythmias in HF where CaMKII is found to be increased

Hemodynamic effects of peri-operative statin therapy in on-pump cardiac surgery patients

Abstract Background Peri-operative statin therapy in cardiac surgery cases is reported to reduce the rate of mortality, stroke, postoperative atrial fibrillation, and systemic inflammation. Systemic inflammation could affect the hemodynamic parameters and stability. We set out to study the effect of statin therapy on perioperative hemodynamic parameters and its clinical outcome. Methods In a single center study from 2006 to 2007, peri-operative hemodynamic parameters of 478 patients, who underwent cardiac surgery with cardiopulmonary bypass, were measured. Patients were divided into those who received perioperative statin therapy (n = 276; statin group) and those who did not receive statin therapy (n = 202; no-statin group). The two groups were compared together using Kolmogorov-Smirnov-Test, Fisher’s-Exact-Test, and Student’s-T-test. A p value  Results There was no significant difference in the preoperative risk factors. Onset of postoperative atrial fibrillation was not affected by statin therapy. Extended hemodynamic measurements revealed no significant difference between the two groups, apart from Systemic Vascular Resistance Index (SVRI) . The no-statin group had a significantly higher SVRI (882 ± 206 vs. 1050 ± 501 dyn s/cm5/m2, p = 0.022). Inotropic support was the same in both groups and no significant difference in the mortality rate was noticed. Also, hemodynamic parameters were not affected by different types and doses of statins. Conclusions Perioperative statin therapy for patients undergoing on-pump coronary bypass grafting or valvular surgery, does not affect the hemodynamic parameters and its clinical outcome.</p

Enhanced late INa induces proarrhythmogenic SR Ca leak in a CaMKII-dependent manner

Objective: Enhanced late Na current (late I-Na) induces Na-dependent Ca overload as well as proarrhythmogenic events on the cellular level that include spatio-temporally uncoordinated diastolic Ca release from the sarcoplasmic reticulum (SR) and delayed afterdepolarizations (DADs). The Ca/calmodulin-dependent protein kinase II (CaMKII) gets activated upon increases in [Ca](1) and mediates diastolic SR Ca leak as well as DADs. Rationale: We hypothesized that increased late I-Na (in disease-comparable ranges) exerts proarrhythmogenic events in isolated ventricular mouse myocytes in a manner depending on CaMKII-dependent SR Ca leak. We further tested whether inhibition of disease-related late I-Na may reduce proarrhythmogenic SR Ca leak in myocytes from failing human hearts. Methods: Ventricular myocytes were isolated from healthy wildtype (WT), failing CaMKII delta c transgenic (TG) mouse, and failing human hearts. ATX-II (0.25-10 nmol/L) was used to enhance late I-Na. Spontaneous Ca loss from the SR during diastole (Ca sparks), DADs, non-triggered diastolic Ca transients in myocytes and premature beats of isometrically twitching papillary muscles were used as readouts for proarrhythmogenic events. CaMKII autophosphorylation was assessed by immunoblots. Late I-Na was inhibited using ranolazine (Ran, 10 mu mol/L) or 'FIX (2 mu mol/L), and CaMKII by KN-93 (1 mu mol/L) or ALP (1 mu mol/L). Results: In WTmyocytes, sub-nanomolar ATX-II exposure (0.5 nmol/L) enhanced late I-Na by -60%, which resulted in increased diastolic SR Ca loss despite unaltered SR Ca content. In parallel, DADs and non-triggered diastolic Ca transients arose. Inhibition of enhanced late I-Na by RAN or TTX significantly attenuated diastolic SR Ca loss and suppressed DADs as well as mechanical altemans in mouse and diastolic SR Ca loss in failing human myocytes. ATX-II caused Ca-dependent CaMKII-activation without changes in protein expression, which was reversible by Ran or AIP. Conversely, CaMKII-inhibition decreased diastolic SR Ca loss, DADs and non-triggered diastolic Ca transients despite ATX-II-exposure. Finally, failing mouse myocytes with increased CaMKII activity (TG CaMKII delta c) showed an even aggravated diastolic SR Ca loss that was associated with an increased frequency of non-triggered diastolic Ca transients upon enhanced late I-Na. Conclusions: Increased late 'Na (in disease-comparable ranges) induces proarrhythmogenic events during diastole in healthy and failing mouse myocytes, which are mediated via CaMKII-dependent SR Ca loss. Inhibition of late I-Na not only attenuated these cellular arrhythmias in mouse myocytes but also in failing human myocytes indicating some antiarrhythmic potential for an inhibition of the elevated late I-Na/CaMKII signaling pathway in this setting. (c) 2014 Elsevier Ltd. All rights reserved

Antiarrhythmic effects of dantrolene in human diseased cardiomyocytes

BACKGROUND Cardiac type 2 ryanodine receptors (RyR(2)s) Play a pivotal role in cellular electrophysiology and contractility. Increased RyR(2)-mediated diastolic sarcoplasmic reticulum (SR) Ca2+ release is linked to heart failure (HF) and arrhythmias. Dantrolene, a drug used for the treatment of malignant hyperthermia, is known to stabilize RyRs in skeletal muscle. OBJECTIVE The purpose of this study was to investigate the effects of dantrolene on arrhythmogenic triggers and contractile function in human atrial fibrillation (AF) and HF cardiomyocytes (CM). METHODS Human CM were isolated from either patients with HF (ventricular) or patients with AF (atrial), and Ca2+ imaging, patch damp, or muscle strip experiments were performed. RESULTS After exposure to dantrolene, human atrial AF and left ventricular HF CM showed significant reductions in proarrhythmic SR Ca" spark frequency and diastolic SR Ca2+ leak. Moreover, dantrolene decreased the frequency of Ca2+ waves and spontaneous Ca" transients in HF CM. Patch-damp experiments revealed that dantrolene significantly suppressed delayed afterdepolarizations in HF and AF CM. Importantly, dantrolene had no effect on action potential duration in AF or in HF CM. In addition, dantrolene had neutral effects on contractile force of human isometrically twitching ventricular HF trabeculae. CONCLUSION Our study showed that dantrolene beneficially influenced disrupted SR Ca2+ homeostasis in human HF and AF CM. Cellular arrhythmogenic triggers were potently suppressed by dantrolene, whereas action potential duration and contractility were not affected. As a clinically approved drug for the treatment of malignant hyperthermia, dantrolene may be a potential antiarrhythmic drug for patients with rhythm disorders and merits further clinical investigation

The combined effects of ranolazine and dronedarone on human atrial and ventricular electrophysiology

Introduction: Pharmacological rhythm control of atrial fibrillation (AF) in patients with structural heart disease is limited. Ranolazine in combination with low dose dronedarone remarkably reduced AF-burden in the phase II HARMONY trial. We thus aimed to investigate the possible mechanisms underlying these results. Methods and results: Patch clamp experiments revealed that ranolazine (5 mu M), low-dose dronedarone (0.3 mu M), and the combination significantly prolonged action potential duration (APD(90)) in atrial myocytes from patients in sinus rhythm (prolongation by 23.5 +/- 0.1%, 31.7 +/- 0.1% and 25.6 +/- 0.1% respectively). Most importantly, in atrial myocytes from patients with AF ranolazine alone, but more the combination with dronedarone, also prolonged the typically abbreviated APD(90) (prolongation by 21.6 +/- 0.1% and 31.9 +/- 0.1% respectively). It was clearly observed that neither ranolazine, dronedarone nor the combination significantly changed the APD or contractility and twitch force in ventricular myocytes or trabeculae from patients with heart failure (HF). Interestingly ranolazine, and more so the combination, but not dronedarone alone, caused hyperpolarization of the resting membrane potential in cardiomyocytes from AF. As measured by confocal microscopy (Fluo-3), ranolazine, dronedarone and the combination significantly suppressed diastolic sarcoplasmic reticulum (SR) Ca2+ leak in myocytes from sinus rhythm (reduction by ranolazine: 89.0 +/- 30.7%, dronedarone: 75.6 +/- 27.4% and combination: 78.0 +/- 272%), in myocytes from AF (reduction by ranolazine: 67.6 +/- 33.7%, dronedarone: 86.5 +/- 31.7% and combination: 81.0 +/- 33.3%), as well as in myocytes from HF (reduction by ranolazine: 64.8 +/- 26.5% and dronedarone: 65.9 +/- 29.3%). Conclusions: Electrophysiological measurements during exposure to ranolazine alone or in combination with low-dose dronedarone showed APD prolongation, cellular hyperpolarization and reduced SR Ca2+ leak in human atrial myocytes. The combined inhibitory effects on various currents, in particular Na+ and K+ currents, may explain the anti-AF effects observed in the HARMONY trial. Therefore, the combination of ranolazine and dronedarone, but also ranolazine alone, may be promising new treatment options for AF, especially in patients with HF, and merit further clinical investigation. (C) 2016 Elsevier Ltd. All rights reserved

Genetic Polymorphisms in Endothelin-1 as Predictors for Long-Term Survival and the Cardiac Index in Patients Undergoing On-Pump Cardiac Surgery

<div><p>Genetic variants within the endothelin-1 gene (<i>EDN1</i>) have been associated with several cardiovascular diseases and may act as genetic prognostic markers. Here, we explored the overall relevance of <i>EDN1</i> polymorphisms for long-term survival in patients undergoing on-pump cardiac surgery. A prospectively collected cohort of 455 Caucasian patients who underwent cardiac surgery with cardiopulmonary bypass was followed up for 5 years. The obtained genotypes and inferred haplotypes were analyzed for their associations with the five-year mortality rate (primary endpoint). The <i>EDN1</i> T-1370G and K198N genotype distributions did not deviate from Hardy–Weinberg equilibrium and the major allele frequencies were 83% and 77%, respectively. The cardiovascular risk factors were equally distributed in terms of the different genotypes and haplotypes associated with the two polymorphisms. The five-year mortality rate did not differ among the different <i>EDN1</i> T-1370G and K198N genotypes and haplotypes. Haplotype analysis revealed that carriers of the G-T (compound <i>EDN1</i> T-1370G G/K198N T) haplotype had a higher cardiac index than did non-carriers (p = 0.0008); however, this difference did not reach significance after adjusting for multiple testing. The results indicate that common variations in <i>EDN1</i> do not act as prognostic markers for long-term survival in patients undergoing on-pump cardiac surgery.</p></div