Cardiac Acoustic Biomarkers in Patients with Heart Failure during Cardiopulmonary Exercise Testing: An Exploratory Study.

Objective Exercise therapy as part of cardiac rehabilitation is one of the most effective treatments for patients with chronic heart failure (HF). The anaerobic threshold (AT) determined by an exhaled gas analysis during cardiopulmonary exercise testing (CPX) is used to prescribe the appropriate level of exercise therapy. However, CPX using an exhaled gas analysis is not widely performed because of its cost, complexity, and the need for skilled staff. Therefore, a simpler and inexpensive method for determining AT without respiratory gas measurements is required in patients with HF. The present study elucidated the relationship between the AT determined by the CPX ventilatory method (CPX-AT) and the AT determined by cardiac acoustic biomarkers (CABs), which are measured by acoustic cardiography (CAB-AT), in HF patients. Methods Patients underwent symptom-limited ramp CPX twice using a cycle ergometer. The ATs determined from the exhaled gas analysis were identified by three independent physicians. CABs, including the first heart sound (S1) and the second heart sound intensities (peak-to-peak amplitudes), electromechanical activation time (EMAT) defined as the time interval from the Q wave onset on electrocardiography to S1, heart rate, and other parameters, were collected during CPX. Patients Forty patients with HF were included in this study. Results A significant correlation (R=0.70; p<0.001) was found between CPX-AT and CAB-AT, using the double product of S1 intensity and heart rate. CAB-AT using S1 intensity also showed a significant correlation with CPX-AT (R=0.71; p<0.001). Conclusion The present study suggests a possible new method for determining AT without respiratory gas measurements in patients with HF.

Impact of Induced Therapeutic Hypothermia by Intravenous Infusion of Ice-Cold Fluids After Hospital Arrival in Comatose Survivors of Out-of-Hospital Cardiac Arrest With Initial Shockable Rhythm.

BACKGROUND: The effect of in-hospital rapid cooling by intravenous ice-cold fluids for comatose survivors of out-of-hospital cardiac arrest (OHCA) is unclear.Methods and Results:From the J-PULSE-HYPO study registry, data for 248 comatose survivors with return of spontaneous circulation (ROSC) who were treated with therapeutic hypothermia (34℃ for 12-72 h) after witnessed shockable OHCA were extracted. Patients were divided into 2 groups by the median collapse-to-ROSC interval (18 min), and then into 2 groups by cooling method (rapid cooling by intravenous ice-cold fluids vs. standard cooling). The primary endpoint was favorable neurological outcome (Cerebral Performance Category of 1 or 2) at 30 days after OHCA. In the whole cohort, the shorter collapse-to-ROSC interval group had significantly higher favorable neurological outcome than the longer collapse-to-ROSC interval group (78.2% vs. 46.8%, P<0.001). In the shorter collapse-to-ROSC interval group, no significant difference was observed in favorable neurological outcome between the 2 cooling groups (rapid cooling group: 79.4% vs. standard cooling group: 77.0%, P=0.75). In the longer collapse-to-ROSC interval group, however, favorable neurological outcome was significant higher in the rapid cooling group than in the standard cooling group (60.7% vs. 33.3%, P<0.01) and the adjusted odds ratio after rapid cooling was 3.069 (95% confidence interval 1.423-6.616, P=0.004). CONCLUSIONS: In-hospital rapid cooling by intravenous ice-cold fluids improved neurologically intact survival in comatose survivors whose collapse-to-ROSC interval was delayed over 18 min after shockable OHCA.

Beneficial effects of dantrolene in the treatment of rhabdomyolysis as a potential late complication associated with COVID-19: a case report.

BACKGROUND: Patients with severe COVID-19 have disorders of the respiratory, cardiovascular, coagulation, skeletal muscle, and central nervous systems. These systemic failures may be associated with cytokine release syndrome, characterized by hyperpyrexia, thrombocytopenia, hyperferritinemia, and the elevation of other inflammatory markers. Rhabdomyolysis with high fever is a complication that is rarely found in COVID-19. The exact relations of these clinical conditions in patients with COVID-19 remain unknown. CASE PRESENTATION: We present the case of a 36-year-old man with severe COVID-19 complicated by rhabdomyolysis and high fever. After admission, his condition continued to deteriorate, with a high body temperature. On day 9, the patient had elevated creatine kinase and myoglobin levels consistent with rhabdomyolysis (26,046 U/L and 3668 ng/mL, respectively). In addition to viral therapy, he was immediately treated with hydration. However, the patient had persistent fever and elevated creatine kinase levels. The patient was diagnosed with malignant hyperthermia as a late complication of COVID-19, although he had no hereditary predisposition to malignant hyperthermia or neuroleptic malignant syndrome. The administration of dantrolene with muscle relaxation and anti-inflammatory function showed potential efficacy for rhabdomyolysis, high fever, and increased plasma inflammatory markers. CONCLUSIONS: Malignant hyperthermia is triggered by not only anesthetic agents but also viral infections. A possible mechanism of malignant hyperthermia is hypersensitivity of calcium release from the sarcoplasmic reticulum. These include mutations in or the activation of the skeletal muscle ryanodine receptor calcium release channel. Dantrolene is a ryanodine receptor antagonist and is used as an anti-inflammatory agent. The administration of dantrolene showed potential efficacy for rhabdomyolysis, high body temperature due to inflammation, and increased inflammatory markers. The underlying mechanism of the association of rhabdomyolysis and high fever in COVID-19 might be similar to the pathogenesis of malignant hyperthermia.

Does Antiarrhythmic Drug During Cardiopulmonary Resuscitation Improve the One-month Survival: The SOS-KANTO 2012 Study.

BACKGROUND: Antiarrhythmic drugs (AAD) are often used for fatal ventricular arrhythmias during cardiopulmonary resuscitation (CPR). However, the efficacy of initial AAD administration during CPR in improving long-term prognosis remains unknown. This study retrospectively evaluated the effect of AAD administration during CPR on 1-month prognosis in the SOS-KANTO 2012 study population. METHODS AND RESULTS: Of the 16,164 out-of-hospital cardiac arrest cases, 1350 shock-refractory patients were included: 747 patients not administered AAD and 603 patients administered AAD. Statistical adjustment for potential selection bias was performed using propensity score matching, yielding 1162 patients of whom 792 patients were matched (396 pairs). The primary outcome was 1-month survival. The secondary outcome was the proportion of patients with favorable neurological outcome at 1 month. Logistic regression with propensity scoring demonstrated an odds ratio (OR) for 1-month survival in the AAD group of 1.92 (P < 0.01), whereas the OR for favorable neurological outcome at 1 month was 1.44 (P = 0.26). CONCLUSIONS: Significantly greater 1-month survival was observed in the AAD group compared with the non-AAD group. However, the effect of ADD on the likelihood of a favorable neurological outcome remains unclear. The findings of the present study may indicate a requirement for future randomized controlled trials evaluating the effect of ADD administration during CPR on long-term prognosis.

Complete occlusion of the left main trunk coronary artery by a cardiac papillary fibroelastoma in a hemodynamically unstable patient.

Papillary fibroelastomas are benign cardiac tumors with high embolic potential. The majority of cases of complete obstruction of the left main trunk (LMT) of the coronary artery are diagnosed via autopsy following sudden death; survival is rare in this setting. We present the case of a 60-year-old woman who underwent stent placement in the LMT three years prior to developing chest pain and cold sweats. On coronary arteriography, the catheter could not be advanced into the LMT due to resistance in the ostium. Insertion of the catheter was achieved after the resolution of resistance via catheterization of the LMT by means of an intra-aortic balloon pump drive system. The LMT was normal, and the patient's circulatory failure improved. The cause of the LMT embolism was a cardiac papillary fibroelastoma. Primary surgical excision is the recommended therapy for symptomatic cardiac papillary fibroelastoma. If the patient is hemodynamically stable, it may be possible to delay surgery. However, the patient in question developed cardiogenic shock secondary to two-vessel obstruction by the tumor. Therefore, even if the tumor had been removed using an intra-aortic balloon pump, the patient may not have survived until surgery. .

Nifekalant Hydrochloride and Amiodarone Hydrochloride Result in Similar Improvements for 24-Hour Survival in Cardiopulmonary Arrest Patients: The SOS-KANTO 2012 Study.

BACKGROUND: Amiodarone (AMD), nifekalant (NIF), and lidocaine (LID) hydrochlorides are widely used for ventricular tachycardia/fibrillation (VT/VF). This study retrospectively investigated the NIF potency and the differential effects of 2 initial AMD doses (≤150 mg or 300 mg) in the Japanese SOS-KANTO 2012 study population. METHODS AND RESULTS: From 16,164 out-of-hospital cardiac arrest cases, 500 adult patients using a single antiarrhythmic drug for shock-resistant VT/VF were enrolled and categorized into 4 groups (73 LID, 47 NIF, 173 AMD-≤150, and 207 AMD-300). Multivariate analyses evaluated the outcomes of NIF, AMD-≤150, or AMD-300 groups versus LID group. Odds ratios (ORs) for survival to admission were 3.21 [95% confidence interval (CI): 1.38-7.44, P < 0.01] in NIF and 3.09 (95% CI: 1.55-6.16, P < 0.01) in AMD-≤150 groups and significantly higher than those of the LID group. However, the OR was 1.78 (95% CI: 0.90-3.51, P = 0.10) in AMD-300 group and was not significant than LID group. ORs for 24-hour survival were 6.68 in NIF, 4.86 in AMD-≤150, and 2.97 in AMD-300, being significantly higher in these groups. CONCLUSIONS: NIF and AMD result in similar improvements for 24-hour survival in cardiopulmonary arrest patients, and this suggest the necessity of a randomized control study.

Changes of cerebral oxygen metabolism and hemodynamics during ECPR with hypothermia measured by near-infrared spectroscopy: a pilot study.

BACKGROUND: The 2010 CPR Guidelines recommend that extracorporeal cardiopulmonary resuscitation (ECPR) using an emergency cardiopulmonary bypass (CPB) should be considered for patients with cardiac arrest. However, it is not yet clear whether this therapy can improve cerebral circulation and oxygenation in these patients. To clarify this issue, we evaluated changes of cerebral blood oxygenation (CBO) during ECPR using near-infrared spectroscopy (NIRS). METHODS: We employed NIRS to measure CBO in the bilateral frontal lobe in patients transported to the emergency room (ER) after out-of-hospital cardiac arrest between November 2009 and June 2011. RESULTS: Fifteen patients met the above criteria. The tissue oxygenation index (TOI) on arrival at the ER was 36.5 %. This increased to 67.8 % during ECPR (P < 0.001). The one patient whose TOI subsequently decreased had a favorable neurological outcome. CONCLUSION: Increase of TOI during ECPR might reflect an improvement in cerebral blood flow, while decrease of TOI after ECPR might reflect oxygen utilization by the brain tissue as a result of neuronal cell survival. NIRS may be useful for monitoring cerebral hemodynamics and oxygen metabolism during CPR.

Prognostic value of venous blood ammonia in patients with out-of-hospital cardiac arrest.

BACKGROUND: Although studies have shown there is a correlation between increased blood ammonia level and hepatic encephalopathy, little information is available for patients with out-of-hospital cardiac arrest. METHODS AND RESULTS: We did a prospective study of 357 adult patients with out-of-hospital cardiac arrest whose venous blood ammonia levels were measured on arrival at the emergency room. The primary endpoint was favorable of neurological outcome to hospital discharge. Of the 357 patients, 25 (7%) had a favorable neurological outcome. The venous ammonia levels were lower in the favorable neurological outcome group than in the unfavorable neurological outcome group (median, 50 µg/dl vs. 210 µg/dl, P<0.0001). The adjusted odds ratio of ammonia levels for favorable neurological outcome was 0.98 (95% confidence interval, 0.96-0.99; P<0.0001). The ammonia cutoff value of 93.0 µg/dl for the identification of favorable neurological outcome had the highest combined sensitivity and specificity, and higher ammonia levels were associated with more accurate negative predictive values (for ammonia levels of 192.5 µg/dl, the negative predictive value was 100%). Hyperammonemia was significantly related to patient variables that had a poor outcome (R=0.439, P<0.001). In addition, there was a significant correlation between venous ammonia level and arterial pH on emergency room arrival (R=0.633, P<0.0001). CONCLUSIONS: The measurement of ammonia was found to provide valuable information regarding neurological outcome to hospital discharge in adult patients with out-of-hospital cardiac arrest.

Early induction of hypothermia during cardiac arrest improves neurological outcomes in patients with out-of-hospital cardiac arrest who undergo emergency cardiopulmonary bypass and percutaneous coronary intervention.

BACKGROUND: Therapeutic hypothermia for comatose survivors of out-of-hospital cardiac arrest has demonstrated neurological benefits. Although early cooling during cardiac arrest enhances efficacy in animal studies, few clinical studies are available. METHODS AND RESULTS: The 171 patients who failed to respond to conventional cardiopulmonary resuscitation were studied prospectively. Patients underwent emergency cardiopulmonary bypass (CPB) plus intra-aortic balloon pumping, with subsequent percutaneous coronary intervention (PCI) if needed. Mild hypothermia (34 degrees C for 3 days) was induced during cardiac arrest or after return of spontaneous circulation. Of the 171 patients, 21 (12.3%) had a favorable neurological outcome at hospital discharge. An unadjusted rate of favorable outcome decreased in a stepwise fashion for increasing quartiles of collapse-to-34 degrees C interval (P=0.016). An adjusted odds ratio for favorable outcome after collapse-to-CPB interval was 0.89 (95% confidence interval (CI) 0.82-0.97) and after CPB-to-34 degrees C interval, 0.99 (95%CI 0.98-0.99) when collapse-to-34 degrees C interval was divided into 2 components. Favorable neurological accuracy of a collapse-to-CPB interval at a cutoff of 55.5 min and CPB-to-34 degrees C interval at a cutoff of 21.5 min was 85.4% and 89.5%, respectively. CONCLUSIONS: Early attainment of a core temperature had neurological benefits for patients with out-of-hospital cardiac arrest who underwent CPB and PCI. (Circ J 2010; 74: 77 - 85).