Wittwer, Erica D.

Background: Percutaneous stellate ganglion blockade (SGB) has been used for drug-refractory electrical storm due to ventricular arrhythmia (VA); however, the effects and long-term outcomes have not been well studied. Methods: This study included 30 consecutive patients who had drug-refractory electrical storm and underwent percutaneous SGB between October 1, 2013, and March 31, 2018. Bupivacaine, alone or combined with lidocaine, was injected into the neck with good local anesthetic spread in the vicinity of the left stellate ganglion (n=15) or both stellate ganglia (n=15). Data were collected for patient clinical characteristics, immediate and long-term outcomes, and procedure-related complications. Results: Clinical characteristics included age, 58±14 years; men, 73.3%; and left ventricular ejection fraction, 34±16%. At 24 hours, 60% of patients were free of VA. Patients whose VA was controlled had a lower hospital mortality rate than patients whose VA continued (5.6% versus 50.0%; P =0.009). Implantable cardioverter-defibrillator interrogation showed a significant 92% reduction in VA episodes from 26±41 to 2±4 in the 72 hours after SGB ( P <0.001). Patients who died during the same hospitalization (n=7) were more likely to have ischemic cardiomyopathy (100% versus 43.5%; P =0.03) and recurrent VA within 24 hours (85.7% versus 26.1%; P =0.009). There were no procedure-related major complications. Conclusions: SGB effectively attenuated electrical storm in more than half of patients without procedure-related complications. Percutaneous SGB may be considered for stabilizing ventricular rhythm in patients for whom other therapies have failed.

AbstractIntroductionAutonomic modulation has been used as a therapy to control recurrent ventricular arrhythmia (VA). This study was to explore stellate ganglion block (SGB) effect on cardiac electrophysiologic properties and evaluate the long‐term outcome of cardiac sympathetic denervation (CSD) for patients with recurrent VA and structural heart disease (SHD).Materials and MethodsPatients who had recurrent VA due to SHD were enrolled prospectively. Electrophysiologic study and ventricular tachycardia (VT) induction were performed before and after left and right SGB. VA burden and long‐term outcomes were assessed for a separate patient group who underwent left or bilateral CSD for drug‐refractory VA due to SHD.ResultsElectrophysiologic study of nine patients showed that baseline mean (SD) corrected sinus node recovery time (cSNRT) increased from 320.4 (73.3) ms to 402.9 (114.2) ms after left and 482.4 (95.7) ms after bilateral SGB (P = .03). SGB did not significantly change P‐R, QRS, and Q‐T intervals and ventricular effective refractory period, nor did the inducibility of VA. Nineteen patients underwent left (n = 14) or bilateral (n = 5) CSD. CSD reduced VA burden and appropriate ICD therapies from a median (interquartile range) of 2.5 (0.4‐11.6) episodes weekly to 0.1 (0.0‐2.4) episodes weekly at 6‐month follow‐up (P = .002). Three‐year freedom from orthotopic heart transplant (OHT) and death was 52.6%. New York Heart Association functional class III/IV and VT rate less than 160 beats per minute were predictors of recurrent VA, OHT, and death.ConclusionSGB increased cSNRT without changing heart rate. CSD was more beneficial for patients with mild‐to‐moderate heart failure and faster VA.

Cardiac vasoplegia remains a significant contributor of morbidity and mortality in cardiac surgery patients after cardiopulmonary bypass. Effective therapeutic options for vasopressor-refractory vasoplegia are limited. We report 3 patients in whom we administered high-dose intravenous ascorbic acid (vitamin C), a cofactor for endogenous catecholamine synthesis, to treat vasoplegia refractory to epinephrine, vasopressin, and norepinephrine after surgery requiring cardiopulmonary bypass. Reductions in vasopressor requirements were observed in all 3 patients, and, in 2 patients, norepinephrine was completely discontinued within 24 hours. Ascorbic acid is a novel potential therapeutic option for cardiac vasoplegia that warrants rigorous prospective studies.

Hydroxocobalamin (vitamin B12a) is an emerging treatment for vasoplegic syndrome (VS) associated with cardiopulmonary bypass (CPB). Given its cost and scarcity, an institutional guideline for its use as a rescue treatment in cases of suspected VS was developed. Hemodynamic variables and vasopressor requirements were reviewed for a series of 24 post-CPB patients who received B12a. Favorable changes in hemodynamic parameters and vasopressor requirements were seen after B12a administration although guideline criteria for VS were inconsistently met. These findings support the continued study of B12a in patients with CPB-associated VS.

Levetiracetam is a first‐line therapy for seizures in critically ill patients because of its clinical efficacy, minimal drug interactions, and wide therapeutic window. The primary mechanism of levetiracetam clearance is renal, and the drug has a low molecular weight. It is hydrophilic and exhibits minimal protein binding. Thus it is expected that levetiracetam will be removed by continuous venovenous hemofiltration (CVVH), with limited clearance by venoarterial extracorporeal membrane oxygenation (ECMO). We describe the case of a 67‐year‐old man who was admitted to the cardiovascular surgery intensive care unit after cardiac arrest and initiation of venoarterial ECMO. His course was complicated by multiorgan dysfunction including acute renal failure requiring CVVH. On hospital day 6, intravenous levetiracetam, at a loading dose of 2000 mg followed by a maintenance dose of 1000 mg every 12 hours, was initiated for new‐onset seizures. The volume of distribution was 0.65 L/kg, and clearance was measured with peak (ranging from 26.5–39.8 μg/ml) and trough (ranging from 13.9–18.2 μg/ml) concentrations. Elimination half‐life ranged from 8.7–10.1 hours. Renal dysfunction reduces levetiracetam clearance, and dosage reductions are recommended to prevent accumulation. Current CVVH dosing recommendations are based on predicted removal without clinical data. The volume of distribution and clearance in this case were similar to those of a normal healthy patient. Based on these results, we recommend considering an initial levetiracetam dose of 1000 mg every 12 hours for patients receiving CVVH, with dosage adjustments based on therapeutic drug monitoring.

The purpose of this case is to describe the complex perioperative management of a 30-year-old woman with congenital heart disease and multiple resternotomies presenting with pulmonary homograft dysfunction and evaluation for percutaneous pulmonary valve replacement. Transvenous, transcatheter Melody valve placement caused left main coronary artery occlusion and cardiogenic shock. An Impella ventricular assist device (VAD) provided rescue therapy during operating room transport for valve removal and pulmonary homograft replacement. ECMO support was required following surgery. Several days later during an attempted ECMO wean, her hemodynamics deteriorated abruptly. Transesophageal and epicardial echocardiography identified pulmonary graft obstruction, requiring homograft revision due to large thrombosis. This case illustrates a role for Impella VAD as bridge to definitive procedure after left coronary occlusion and describes management of complex perioperative ECMO support challenges.