[Short version of the 2nd edition of the German-Austrian S3 guidelines "Cardiogenic shock complicating myocardial infarction-Diagnosis, monitoring and treatment"]. / Kurzversion der 2. Auflage der deutsch-österreichischen S3-Leitlinie "Infarkt-bedingter Kardiogener Schock ­ Diagnose, Monitoring und Therapie".

BACKGROUND: The present guidelines ( http://leitlinien.net ) focus exclusively on cardiogenic shock due to myocardial infarction (infarction-related cardiogenic shock, ICS). The cardiological/cardiac surgical and the intensive care medicine strategies dealt with in these guidelines are essential to the successful treatment and survival of patients with ICS; however, both European and American guidelines on myocardial infarction and heart failure and also position papers on cardiogenic shock focused mainly on cardiological aspects. METHODS: Evidence on the diagnosis, monitoring and treatment of ICS was collected and recommendations compiled in a nominal group process by delegates of the German Cardiac Society (DGK), the German Society for Medical Intensive Care Medicine and Emergency Medicine (DGIIN), the German Society for Thoracic and Cardiovascular Surgery (DGTHG), the German Society for Anaesthesiology and Intensive Care Medicine (DGAI), the Austrian Society for Internal and General Intensive Care Medicine (ÖGIAIM), the Austrian Cardiology Society (ÖKG), the German Society for Prevention and Rehabilitation of Cardiovascular Diseases (DGPR) and the German Interdisciplinary Association for Intensive Care and Emergency Medicine (DIVI), under the auspices of the Working Group of the Association of Medical Scientific Societies in Germany (AWMF). If only poor evidence on ICS was available, general study results on intensive care patients were inspected and presented in order to enable analogue conclusions. RESULTS: A total of 95 recommendations, including 2 statements were compiled and based on these 7 algorithms with defined instructions on the course of treatment.

Pathophysiological and therapeutic implications in patients with atrial fibrillation and heart failure.

Heart failure and atrial fibrillation are common and responsible for significant mortality of patients. Both share the same risk factors like hypertension, ischemic heart disease, diabetes, obesity, arteriosclerosis, and age. A variety of microscopic and macroscopic changes favor the genesis of atrial fibrillation in patients with preexisting heart failure, altered subcellular Ca2+ homeostasis leading to increased cellular automaticity as well as concomitant fibrosis that are induced by pressure/volume overload and altered neurohumoral states. Atrial fibrillation itself promotes clinical deterioration of patients with preexisting heart failure as atrial contraction significantly contributes to ventricular filling. In addition, atrial fibrillation induced tachycardia can even further compromise ventricular function by inducing tachycardiomyopathy. Even though evidence has been provided that atrial functions significantly and independently of confounding ventricular pathologies, correlate with mortality of heart failure patients, rate and rhythm controls have been shown to be of equal effectiveness in improving mortality. Yet, it also has been shown that cohorts of patients with heart failure benefit from a rhythm control concept regarding symptom control and hospitalization. To date, amiodarone is the most feasible approach to restore sinus rhythm, yet its use is limited by its extensive side-effect profile. In addition, other therapies like catheter-based pulmonary vein isolation are of increasing importance. A wide range of heart failure-specific therapies are available with mixed impact on new onset or perpetuation of atrial fibrillation. This review highlights pathophysiological concepts and possible therapeutic approaches to treat patients with heart failure at risk for or with atrial fibrillation.

Mild hypothermia induces incomplete left ventricular relaxation despite spontaneous bradycardia in pigs.

AIM: Mild hypothermia (MH) decreases left ventricular (LV) end-diastolic capacitance. We sought to clarify whether this results from incomplete relaxation. METHODS: Ten anaesthetized pigs were cooled from normothermia (NT, 38 °C) to MH (33 °C). LV end-diastolic pressure (LVPed), volume (LVVed) and pressure-volume relationships (EDPVRs) were determined during stepwise right atrial pacing. LV capacitance (i.e. LVVed at LVPed of 10 mmHg, LV VPed10) was derived from the EDPVR. Pacing-induced changes of diastolic indices (LVPed, LVVed and LV VPed10) were analysed as a function of (i) heart rate and (ii) the ratio between diastolic time interval (t-dia) and LV isovolumic relaxation constant τ, which was calculated using a logistic fit (τL ) and monoexponential fit with zero asymptote (τZ ) and nonzero asymptote (τNZ ). RESULTS: Mild hypothermia decreased heart rate (85 ± 4 to 68 ± 3 bpm), increased τL (22 ± 1 to 57 ± 4 ms), τZ (26 ± 2 to 56 ± 5 ms) and τNZ (41 ± 1 to 96 ± 5 ms), decreased t-dia/τ ratios, and shifted the EDPVR leftwards compared to NT (all P < 0.05). During NT, pacing at ≥140 bpm shifted the EDPVR progressively leftwards. During MH, relationships between diastolic indices and heart rate were shifted towards lower heart rates compared to NT. However, relationships between diastolic indices and t-dia/τ during NT and MH were superimposable. CONCLUSION: We conclude that the loss of LV end-diastolic capacitance during MH can be explained at least in part by slowed LV relaxation. MH thereby is an example of incomplete LV relaxation at a spontaneous low heart rate. Caution may be advised, when heart rate is increased in patients treated with MH.

JTV519 (K201) reduces sarcoplasmic reticulum Ca²âº leak and improves diastolic function in vitro in murine and human non-failing myocardium.

BACKGROUND AND PURPOSE: Ca²âº leak from the sarcoplasmic reticulum (SR) via ryanodine receptors (RyR2s) contributes to cardiomyocyte dysfunction. RyR2 Ca²âº leak has been related to RyR2 phosphorylation. In these conditions, JTV519 (K201), a 1,4-benzothiazepine derivative and multi-channel blocker, stabilizes RyR2s and decrease SR Ca²âº leak. We investigated whether JTV519 stabilizes RyR2s without increasing RyR2 phosphorylation in mice and in non-failing human myocardium and explored underlying mechanisms. EXPERIMENTAL APPROACH: SR Ca²âº leak was induced by ouabain in murine cardiomyocytes. [Ca²âº]-transients, SR Ca²âº load and RyR2-mediated Ca²âº leak (sparks/waves) were quantified, with or without JTV519 (1 µmol·L⁻¹). Contribution of Ca²âº -/calmodulin-dependent kinase II (CaMKII) was assessed by KN-93 and Western blot (RyR2-Ser(2814) phosphorylation). Effects of JTV519 on contractile force were investigated in non-failing human ventricular trabeculae. KEY RESULTS: Ouabain increased systolic and diastolic cytosolic [Ca²âº](i) , SR [Ca²âº], and SR Ca²âº leak (Ca²âº spark (SparkF) and Ca²âº wave frequency), independently of CaMKII and RyR-Ser(2814) phosphorylation. JTV519 decreased SparkF but also SR Ca²âº load. At matched SR [Ca²âº], Ca²âº leak was significantly reduced by JTV519, but it had no effect on fractional Ca²âº release or Ca²âº wave propagation velocity. In human muscle, JTV519 was negatively inotropic at baseline but significantly enhanced ouabain-induced force and reduced its deleterious effects on diastolic function. CONCLUSIONS AND IMPLICATIONS: JTV519 was effective in reducing SR Ca²âº leak by specifically regulating RyR2 opening at diastolic [Ca²âº](i) in the absence of increased RyR2 phosphorylation at Ser(2814) , extending the potential use of JTV519 to conditions of acute cellular Ca²âº overload.