Occurrence of hemodynamic changes following administration of rocuronium in a dog presenting for an ophthalmic procedure.

A 10-year-old, neutered male, Golden Retriever dog presented for surgical correction of a descemetocele. Acepromazine (0.02 mg/kg) and methadone (0.5 mg/kg) were administered intramuscularly for sedation, propofol (2 mg/kg) and midazolam (0.2 mg/kg) were administered intravenously for anaesthetic induction and isoflurane in oxygen was utilised for anaesthetic maintenance. Rocuronium (0.5 mg/kg), a neuromuscular blocking agent, was administered intravenously to facilitate central positioning of the eye for surgery. Within 10 min of rocuronium administration, the dog became tachycardic and hypotensive. Hemodynamic aberrations did not resolve with initial interventions but were successfully mitigated with the administration of diphenhydramine (0.8 mg/kg) intravenously. The dog remained stable throughout the remainder of the procedure and experienced a smooth and uneventful recovery. While it is difficult to confirm that the hemodynamic changes observed in this clinical case resulted solely from administration of rocuronium, the observance of the cardiovascular changes, timing of events and response to therapy suggest that rocuronium elicited a histamine response that was successfully treated with diphenhydramine.

The Plumber Versus Electrician Dilemma: To Bypass or to Defibrillate?

We present a unique case of an 80-year-old male who presented to our emergency department following cardiac defibrillation when he was found to be in polymorphic ventricular tachycardia (VT) after a syncopal event while at cardiac rehabilitation. He had known coronary artery disease and had a four-vessel coronary artery bypass graft (CABG) 20 years prior to presentation. He underwent left heart catheterization (LHC) two months prior to the syncopal event for worsening shortness of breath and the decision at that time was to proceed with medical management and intervene with redo-CABG if shortness of breath did not improve or progressively worsened. While admitted under our care after the polymorphic VT event, we faced the dilemma of whether to proceed with redo-CABG first since cardiac ischemia is a common cause of polymorphic VT or whether to insert an implantable cardioverter-defibrillator (ICD) before proceeding with redo-CABG. We present the current literature that addresses ICD implantation for secondary prevention and our approach to this complicated case.

Variations in the threshold's values for border zone and dense scar produce significant changes in the scar parameters obtained by ADAS-3D.

BACKGROUND: ADAS-3D software elaborates Cardiac Magnetic Resonance (CMR) images to obtain a quantitative evaluation of dense scar and border zone (BZ), including BZ channels, which can be useful for ventricular tachycardia ablation and for risk-stratification. However, most prior reports with ADAS-3D used flexible thresholds (60%±5% and 40%±5% of maximum pixel signal intensity -PSI) to define dense scar and BZ. It is unknown which is the impact of such variations of the thresholds values on the measurements obtained with ADAS-3D. OBJECTIVE: To quantify the degree of change in ADAS-3D measurements when different thresholds for dense scar and BZ are employed. METHODS: Single-center retrospective observational cohort study including 87 consecutive patients with previous myocardial infarction who underwent CMR. ADAS-3D software semi-automatically processed CMR sequences. We compared the scar measurements obtained using the 9 possible combinations of thresholds (55%/60%/65% and 35%/40%/45% of maximum PSI). RESULTS: The overall comparison between thresholds showed highly significant differences (p<0.001) in all scar parameters. Not a single patient maintained the same number of BZ channels with all the thresholds settings. A percentage difference of up to 200% in BZ channels numbers and channels mass was observed in all 36 comparisons. An absolute difference of up to 10 channels was also recorded. Of note, the highest median channel mass (obtained with the thresholds 35-65) was 59-fold higher as compared to the lowest one (obtained with the 45-55 cut-offs). CONCLUSIONS: Variations in threshold values result in statistically significant and high-magnitude changes in the quantification of scar parameters by ADAS-3D.

Predicting severe outcomes in pediatric trauma patients: Shock index pediatric age-adjusted vs. age-adjusted tachycardia.

INTRODUCTION: When an injured patient arrives in the Emergency Department (ED), timely and appropriate care is crucial. Shock Index Pediatric Age-Adjusted (SIPA) has been shown to accurately identify pediatric patients in need of emergency interventions. However, no study has evaluated SIPA against age-adjusted tachycardia (AT). This study aims to compare SIPA with AT in predicting outcomes such as mortality, severe injury, and the need for emergent intervention in pediatric trauma patients. MATERIAL AND METHODS: This is a retrospective cross-sectional analysis of patient data abstracted from the Trauma Quality Improvement Program Participant Use Files (TQIP PUFs) for years 2013-2020. Patients aged 4-16 with blunt mechanism of injury and injury severity score (ISS) > 15 were included. 36,517 children met this criteria. Sensitivity, specificity, overtriage, and undertriage rates were calculated to compare the effectiveness of AT and elevated SIPA as predictors of severe injuries and need for emergent intervention. Emergent interventions included craniotomy, endotracheal intubation, thoracotomy, laparotomy, or chest tube placement within 24 h of arrival. RESULTS: AT classified 59% of patients as "high risk," while elevated SIPA identified 26%. Compared to AT patients, a greater proportion of patients with elevated SIPA required a blood transfusion within 24 h (22% vs. 12%, respectively; p < 0.001). In-hospital mortality was higher for the elevated SIPA group than AT (10% vs. 5%, respectively; p < 0.001) as well as the need for emergent operative interventions (43% vs. 32% respectively; p < 0.001). Grade 3 or higher liver/spleen lacerations requiring blood transfusion were also more common among elevated SIPA patients than AT patients (8% vs. 4%, respectively; p < 0.001). AT demonstrated greater sensitivity but lower specificity compared to SIPA across all outcomes. AT showed improved overtriage and undertriage rates compared to SIPA, but this is attributed to identifying a large proportion of the sample as "high risk." CONCLUSIONS: AT outperforms SIPA in sensitivity for mortality, injury severity and emergent interventions in pediatric trauma patients while the specificity of SIPA is high across these outcomes.

Longitudinal reduction in fluoroscopy with continued use of 3-dimensional electroanatomic mapping systems in catheter ablation of supraventricular tachycardia - then and now.

BACKGROUND: Catheter ablation is a first-line treatment for symptomatic, recurrent supraventricular tachycardia (SVT). This study aims to demonstrate if 3D-electroanatomic mapping (EAM) during SVT ablation reduces fluoroscopy time (FT) and determine if further reductions in FT are observed longitudinally. METHODS: All cases of SVT ablation between May 2011-May 2022 at a single tertiary centre were prospectively recruited. FT between the cohorts with and without EAM were compared. Within the EAM subset, the trend of FT across the years was analysed. RESULTS: There were 1758 cases included, 563 without EAM, 1195 with EAM. EAM was associated with a longer procedure time (mean + 8.8 min, p = 0.001), but with mean reductions in FT and dose area product (DAP) by 19.6 min and 18 621 mGy*cm2 respectively (p < 0.001). There was comparable efficacy without any increase in complication rates. Over time (2011-2022), further reduction in FT of 0.9 min year on year was observed (p = 0.001). Between 2011 and 2017, there was a significant reduction in FT of 1.1 min year on year (p = 0.019), which was not observed from 2017 onwards (p = 0.061). The greatest reduction in FT was after the first year of adoption. CONCLUSION: EAM in SVT ablation reduces fluoroscopy use. FT was initially observed to reduce further over time before plateauing, likely due to increased operator experience. While there is increased interest in zero fluoroscopy SVT ablation, complementary use of fluoroscopy may still be necessary in complex cases.

Rare Variant in MRC2 Associated With Familial Supraventricular Tachycardia and Wolff-Parkinson-White Syndrome.

BACKGROUND: Accessory pathways are a common cause of supraventricular tachycardia (SVT) and can lead to sudden cardiac death in otherwise healthy children and adults when associated with Wolff-Parkinson-White syndrome. The goal of this study was to identify genetic variants within a large family with structurally normal hearts affected by SVT and Wolff-Parkinson-White syndrome and determine causality of the gene deficit in a corresponding mouse model. METHODS: Whole exome sequencing performed on 2 distant members of a 3-generation family in which multiple members were affected by SVT or Wolff-Parkinson-White pattern (preexcitation) on ECG identified MRC2 as a candidate gene. Serial electrocardiograms, intracardiac electrophysiology studies, echocardiography, optical mapping studies, and histology were performed on both Mrc2 mutant and WT (wild-type) mice. RESULTS: A rare HET (heterozygous) missense variant c.2969A>G;p.Glu990Gly (E990G) in MRC2 was identified as the leading candidate gene variant segregating with the cardiac phenotype following an autosomal-dominant Mendelian trait segregation pattern with variable expressivity. In vivo electrophysiology studies revealed reentrant SVT in E990G mice. Optical mapping studies in E990G mice demonstrated abnormal retrograde conduction, suggesting the presence of an accessory pathway. Histological analysis of E990G mouse hearts showed a disordered ECM (extracellular matrix) in the annulus fibrosus. Finally, Mrc2 knockdown in human cardiac fibroblasts enhanced accelerated cell migration. CONCLUSIONS: This study identified a rare nonsynonymous variant in the MRC2 gene in individuals with familial reentrant SVT, Wolff-Parkinson-White ECG pattern, and structurally normal hearts. Furthermore, Mrc2 knock-in mice revealed an increased incidence of reentrant SVT and bypass tract formation in the setting of preserved cardiac structure and function.

High-Degree Atrioventricular Block and Torsades De Pointes in Severe Aortic Stenosis Treated With Transcatheter Aortic Valve Replacement.

Severe aortic stenosis (AS) significantly elevates cardiovascular risk, predisposing patients to high-degree atrioventricular (AV) block and life-threatening tachyarrhythmias, including torsades de pointes (TdP). This case report presents a patient with severe AS who developed high-degree AV block and, subsequently, TdP, highlighting the interplay between bradycardia and mechanisms that trigger ventricular tachycardias. The case underscores the importance of identifying and managing these risk factors to improve patient outcomes.

Complex Pulmonary Arteriovenous Fistula Presented With Ventricular Tachycardia and Type 2 Acute Myocardial Infarction.

Pulmonary arteriovenous fistula (PAVF) is a rare congenital vascular malformation primarily manifested as dyspnea, migraine, ischemic stroke, hemoptysis, and nervous system complications. However, in our case, an 18-year-old male patient with PAVF presented with sudden onset of ventricular tachycardia and type 2 acute myocardial infarction as initial symptoms. A diagnosis was achieved through pulmonary artery computer tomography angiography (CTA) and three-dimensional (3D) computed tomography (CT) reconstruction, revealing a complex and giant PAVF. Following multidisciplinary team (MDT) consultation, the patient underwent thoracoscopic surgery and experienced a successful recovery during follow-up.

Simultaneous Ablation of Ventricular Tachycardia and Hemodynamic Improvement of Mid-ventricular Obstructive Hypertrophic Cardiomyopathy by Coronary Venous Ethanol Ablation.

Transvenous coronary ethanol ablation may be successfully applied to simultaneously treat ventricular arrhythmia superimposed within a segment of hypertrophic cardiomyopathy. This presentation nicely describes this emerging technique for ventricular tachycardia ablation and identifies potential additional benefits of venous ethanol administration in patients with left ventricular obstructive physiology.

Deep abdominal breathing reduces heart rate and symptoms during orthostatic challenge in patients with postural orthostatic tachycardia syndrome.

BACKGROUND AND PURPOSE: This study investigated the effects of deep abdominal breathing on cardiovascular parameters and symptoms in patients with postural orthostatic tachycardia syndrome (POTS) during head-up tilt-table (HUT) challenge. METHODS: Thirty POTS patients completed two consecutive rounds of 10-min HUT in a crossover design. One round was HUT without intervention, and one round combined the HUT with deep breathing at a rate of 6 breaths/min. Cardiovascular parameters, including mean blood pressure and maximum and mean heart rate (HR), were measured supine and standing. Symptoms were assessed using the Vanderbilt Orthostatic Symptom Score (VOSS). RESULTS: During the breathing technique, the mean HR increase was -7.35 bpm (95% confidence interval [CI] = -11.71 to -2.98), and the maximum HR increase was -6.27 bpm (95% CI = -11.85 to -0.68, p = 0.041), significantly lower compared to normal breathing. Additionally, improvements were observed in all absolute cardiovascular parameters during standing, with VOSS symptoms simultaneously and significantly decreasing by -5.38 (95% CI = -10.43 to -0.36). CONCLUSIONS: Slow deep abdominal breathing can act as a simple technique to reduce the standing HR increase upon HUT in patients with POTS. This suggests that modulation of the cardiopulmonary neurocircuits and the respiratory pump may reduce HR increase and symptoms in patients with POTS. The findings of this study highlight the use of a safe, zero-cost, and simple behavioral tool to suggest to POTS patients for symptom relief apart from standard treatment. The observed improvements in cardiovascular parameters and symptoms offer a promising therapeutic approach for patients in times of inadequate treatment options.

QT Prolongation and Torsade De Pointes After Catheter Ablation for Persistent Atrial Fibrillation in a Patient With Tachycardia-Induced Cardiomyopathy: A Case Report.

Atrial fibrillation (AF) is the most common cause of tachycardia-induced cardiomyopathy (TIC). A 75-year-old woman was referred to our hospital for catheter ablation for persistent AF. On admission, transthoracic echocardiography (TTE) revealed diffuse left ventricular (LV) hypokinesis, which was suspected to be due to TIC. Catheter ablation was performed on the fifth day of hospitalization, and Torsade de Pointes (TdP) appeared on the sixth day. The serum concentration of bepridil and potassium was below the reference level. An electrocardiogram revealed marked QT prolongation, giant-negative T waves, and T-wave alternans on the seventh day of hospitalization. Cardiac magnetic resonance imaging with no contrast indicated diffuse mild LV hypokinesis, mild prolonged native T1, and no evidence of myocardial edema at T2. Coronary angiography revealed normal coronary arteries, and the ergonovine stress test results were negative. The results for five long QT syndrome susceptibility genes, including the three major genes, were negative. Subsequently, QT prolongation, giant-negative T waves, and LV dysfunction improved without treatment. This case report highlights the importance of risk management for AF patients with TIC scheduled for catheter ablation and carefully evaluating the risks of QT prolongation. Moreover, patients with TIC can experience marked QT prolongation and TdP during the perioperative period of catheter ablation. Therefore, caution should be required.

Effect of ultrashort-acting ß-blockers on 28-day mortality in patients with sepsis with persistent tachycardia despite initial resuscitation: a meta-analysis of randomized controlled trials and trial sequential analysis.

Purpose: This meta-analysis aims to identify whether patients with sepsis who have persistent tachycardia despite initial resuscitation can benefit from ultrashort-acting ß-blockers. Materials and methods: Relevant studies from MEDLINE, the Cochrane Library, and Embase were searched by two independent investigators. RevMan version 5.3 (Cochrane Collaboration) was used for statistical analysis. Results: A total of 10 studies were identified and incorporated into the meta-analysis. The results showed that the administration of ultrashort-acting ß-blockers (esmolol/landiolol) in patients with sepsis with persistent tachycardia despite initial resuscitation was significantly associated with a lower 28-day mortality rate (risk ratio [RR], 0.73; 95% confidence interval [CI], 0.57-0.93; and p˂0.01). Subgroup analysis showed that the administration of esmolol in patients with sepsis was significantly associated with a lower 28-day mortality rate (RR, 0.68; 95% CI, 0.55-0.84; and p˂0.001), while there was no significant difference between the landiolol and control groups (RR, 0.98; 95% CI, 0.41-2.34; and p = 0.96). No significant differences between the two groups were found in 90-day mortality, mean arterial pressure (MAP), lactate (Lac) level, cardiac index (CI), and troponin I (TnI) at 24 h after enrollment. Conclusion: The meta-analysis indicated that the use of esmolol in patients with persistent tachycardia, despite initial resuscitation, was linked to a notable reduction in 28-day mortality rates. Therefore, this study advocates for the consideration of esmolol in the treatment of sepsis in cases where tachycardia persists despite initial resuscitation.