Exploratory use of intraprocedural transesophageal echocardiography to guide implantation of the leadless pacemaker.

Background: Fluoroscopy is the standard tool for transvenous implantation of traditional and leadless pacemakers (LPs). LPs are used to avoid complications of conventional pacemakers, but there still is a 6.5% risk of major complications. Mid-right ventricular (RV) septal device implantation is suggested to decrease the risk, but helpful cardiac landmarks cannot be visualized under fluoroscopy. Transesophageal echocardiography (TEE) is an alternative intraprocedural imaging method. Objective: The purpose of this study was to explore the spatial relationship of the LP to cardiac landmarks via TEE and their correlations with electrocardiographic (ECG) parameters, and to outline an intraprocedural method to confirm mid-RV nonapical lead positioning. Methods: Fifty-six patients undergoing implantation of LP with TEE guidance were enrolled in the study. Device position was evaluated by fluoroscopy, ECG, and TEE. Distances between the device and cardiac landmarks were measured by TEE and analyzed with ECG parameters with and without RV pacing. Results: Mid-RV septal positioning was achieved in all patients. TEE transgastric view (0°-40°/90°-130°) was the optimal view for visualizing device position. Mean tricuspid valve-LP distance was 4.9 ± 0.9 cm, mean pulmonary valve-LP distance was 4.2 ± 1 cm, and calculated RV apex-LP distance was 2.9 ± 1 cm. Mean LP paced QRS width was 160.8 ± 28 ms and increased from 117.2 ± 34 ms at baseline. LP RV pacing resulted in left bundle branch block pattern on ECG and 37.8% QRS widening by 43.5 ± 29 ms. Conclusion: TEE may guide LP implantation in the nonapical mid-RV position. Further studies are required to establish whether this technique reduces implant complications compared with conventional fluoroscopy.

A 70-Year-Old Man With Conspicuous Thigh Pain and ST-Segment Elevations.

CASE PRESENTATION: A 70-year-old man presented to the ED with sudden onset of left thigh pain followed by transient chest discomfort. His history included cerebrovascular disease, hypertension, and cocaine and methamphetamine use. Physical examination revealed an uncomfortable male subject with a temperature of 37 °C, heart rate of 129 beats/min, BP of 130/65 mm Hg, and 98% oxygen saturation on room air. There was point tenderness in the left lateral thigh without erythema, swelling, or overlying skin changes. His cardiac examination revealed an irregular tachycardia at 129 beats/min and normal first and second heart sounds without murmurs, gallops, or rubs. The remainder of the examination was unremarkable.

Impact of hypothermia on cardiac performance during targeted temperature management after cardiac arrest.

INTRODUCTION: Targeted temperature management (TTM) is a well-accepted neuro-protective intervention in the management of comatose survivors of cardiac arrest (CA). However, the impact of TTM on cardiac performance has not been adequately evaluated. METHODS: We reviewed data on consecutive CA survivors undergoing TTM at a quaternary cardiac intensive care unit between January 2015 and June 2017. Enrollment was restricted to cases with invasive hemodynamics (iHDs) at TTM initiation, every 8 h at target temperature (32-34 °C) and at completion of rewarming (>36 °C), unless precluded by mortality. Cardiac index and cardiac index-derived variables were adjusted for a decreased oxygen consumption during hypothermia. We assessed the serial impact of cooling on iHDs and cardiac performance utilizing longitudinal data analysis accounting for the effects of time as surrogate for the expected change from the post arrest syndrome and instituted treatments. A Frank-Starling construct was used to evaluate changes in cardiac contractility. RESULTS: We evaluated the effects of cooling on iHDs and cardiac performance in 46 CA survivors. Heart rate decreased with cooling (p < 0.001), to return to baseline after rewarming (p = 0.6). Mean arterial pressure and pulmonary wedge pressure decreased by cooling (p < 0.001 for both), with sustained improvement after rewarming (p < 0.001 for both). Systemic vascular resistance was unaffected by hypothermia (p > 0.05). Left stroke work index increased with cooling (p < 0.001), with return to baseline after rewarming (p = 0.6). Cooling was associated with a left-upward shift in the Frank-Starling curve indicative of increased contractility. CONCLUSION: Mild hypothermia in CA survivors appears associated to positive changes in iHDs and cardiac performance, including a potential increase in cardiac contractility. Larger studies are needed to conclusively confirm these findings.

Invasive Hemodynamics and Outcomes in Cardiac Arrest Survivors Undergoing Targeted Temperature Management.

Most important prognostic factors in the postcardiac arrest patients who underwent targeted temperature management (TTM) derive from the periarrest period. Whether early invasive hemodynamics predict survival or neurologic outcomes remains unknown. We retrospectively reviewed all comatose survivors of cardiac arrest who underwent TTM at the Coronary Intensive Care Unit of a Quaternary Center between January 2015 and June 2017. Patients were required to have a set of invasive hemodynamics available at initiation of TTM to be included. Those with cooling initiated before admission and temperature of <36°C before obtaining hemodynamics were excluded. Univariate logistic and multivariate regression were conducted to test whether cardiac index (Fick-cardiac index ≥2.2 vs <2.2 L/min/m2), pulmonary capillary wedge pressure (PCWP ≥18 vs <18 mm Hg), systemic vascular resistance (SVR >1200 vs 800 to 1200 vs <800 dynes⋅s/cm5) or Forrester hemodynamic profiles were predictive of survival and favorable neurologic outcomes at hospital discharge. Total of 52 consecutive arrest survivors who underwent TTM were studied demonstrating a wide variability in invasive hemodynamic parameters. There was no association between cardiac index (p = 0.45 and p = 0.10), PCWP (p = 0.90 and p = 0.60), SVR (0.95 and p = 0.17) or Forrester hemodynamic profiles (p = 0.40 and p = 0.42) and survival or favorable neurologic outcome at discharge. In conclusion, comatose arrest survivors who underwent TTM presents with a wide spectrum of invasive hemodynamics highlighting the heterogeneity of the postcardiac arrest syndrome. Early invasive hemodynamics did not predict survival or favorable neurologic outcomes at hospital discharge.

Meta-analysis of Placebo-Controlled Randomized Controlled Trials on the Prevalence of Statin Intolerance.

The prevalence of intolerance varies widely. Stopping statin therapy is associated with worse outcomes in patients with cardiovascular disease. Despite extensive studies, the benefits and risks of statins continue to be debated by clinicians and the lay public. We searched the PubMed, Medline, and Cochrane Central Register of Controlled Trials (CENTRAL) databases for all randomized controlled trials of statins compared with placebo. Studies were included if they had ≥1,000 participants, had patients who were followed up for ≥1 year, and reported rates of drug discontinuation. Studies were pooled as per the random effects model. A total of 22 studies (statins = 66,024, placebo = 63,656) met the inclusion criteria. The pooled analysis showed that, over a mean follow-up of 4.1 years, the rates of discontinuation were 13.3% (8,872 patients) for statin-treated patients and 13.9% (8,898 patients) for placebo-treated patients. The random effects model showed no significant difference between the placebo and statin arms (odds ratio [OR] = 0.99, 95% confidence interval [CI] = 0.93 to 1.06). The results were similar for both primary prevention (OR = 0.98, 95% CI = 0.92 to 1.05, p = 0.39) and secondary prevention (OR = 0.92, 95% CI = 0.83 to 1.05, p = 0.43) studies. The pooled analysis suggested that the rates of myopathy were also similar between the statins and placebos (OR = 1.2, 95% CI = 0.88 to 1.62, p = 0.25). In conclusion, this meta-analysis of >125,000 patients suggests that the rate of drug discontinuation and myopathy does not significantly differ between statin- and placebo-treated patients in randomized controlled trials. These findings are limited by the heterogeneity of results, the variable duration of follow-up, and the lower doses of statins compared with contemporary clinical practice.