Efficacy of prescribing Inderal for polymorphic ventricular tachycardia in a young patient with the normal QT interval: A case report study.

Polymorphic ventricular tachycardia (PVT) is a group of life-threatening heart rhythm disorders. These arrhythmias share similar electrocardiographic characteristics but require different modes of therapy for effective treatment. It is important to note that the medications that are considered the first-line treatment for one type of PVT may not be appropriate for another type, and may worsen the condition. Therefore, it is crucial to accurately diagnose the type of PVT before initiating treatment to provide the most effective therapy for the patient. A 42-year-old man was admitted to the emergency department with dyspnea, Levine sign, and severe chest pain. His electrocardiogram showed ST elevation, and the QT interval was normal. The patient was sent to the cath lab based on the treatment protocols. According to the results of angiography, three coronary arteries were severely obstructed. His coronary arteries did not open during percutaneous coronary intervention; thus, the healthcare team decided on open heart surgery. He suffered from recurrent PVT following open heart surgery and did not respond to any of the drugs suitable for this type of tachycardia. Inderal prevented the recurrence of ventricular tachycardia (VT) in a patient with polymorphic VT without QT prolongation, contrary to the healthcare team's expectations. Inderal was used as the last line of treatment because this patient's arrhythmia was polymorphic VT without QT prolongation. Inderal is typically used for treating VT in patients with long QT syndromes and heart structural disorders. This case report aims to highlight the impact of Inderal on polymorphic tachycardia, specifically in cases where the QT interval is not elongated. In this particular case, the standard treatment approaches were ineffective in preventing reversibility, but Inderal proved to be successful. Therefore, we feel it is important to document and share this case.

Flecainide toxicity-Clinical diagnosis and management of an urgent condition.

Clinical suspicion, clinical presentation, and electrocardiogram can help clinicians diagnose flecainide toxicity. Currently, there are no guidelines for the management of patients with flecainide toxicity. Sodium bicarbonate, lipid emulsion therapy, and extracorporeal life support have been used in this setting. Amiodarone and lidocaine can be used for the management of wide QRS complex tachycardias in hemodynamically stable patients with flecainide toxicity.

Safety of dofetilide in stable patients and investigating traits of susceptibility to torsade de pointes.

Background: Atrial fibrillation is the most prevalent cardiac arrhythmia, presenting symptomatic patients with diminished quality of life and worsening of heart failure. Dofetilide, a class 3 antiarrhythmic agent, is a proven and safe rhythm control medication. Initial risk of QT prolongation leading to torsade de pointes (TdP) necessitates a standard protocol mandating hospitalization for three days for initiation. Objectives: To assess safety when adhering to initiation protocol and identify traits for susceptibility to TdP in elective dofetilide admissions. Methods: We conducted a retrospective study involving patients admitted to Mayo Clinic sites across four states for elective inpatient initiation of dofetilide between 2003 and 2022. Patients' charts underwent review, focusing on dofetilide-related TdP occurrences, baseline characteristics including QT intervals, laboratory values, comorbidities, and concomitant medications. Patients who experienced TdP were subjected to further evaluation to identify potential risk factors. Results: Of 2036 patients identified, mean age 66.4 ± 11.4 years, and 67.2 % male, 16 experienced dofetilide-related TdP (incidence rate 0.79%). Notably, 81% (13/16) of TdP cases occurred in patients who deviated from the FDA/manufacturer algorithm protocol. The concomitant use of active intravenous diuretic therapy, digoxin, and QT-prolonging drugs emerged as identifiable risk factors. Additionally, females exhibited a higher incidence of TdP (1.5%) than males (0.44%) {odd ratio [OR] 3.46; P = 0.017}. Conclusion: Overall incidence of TdP related to dofetilide initiation was low (0.79%). Adherence to protocol during elective hospital admissions appears extraordinarily safe. Patients who did not require concurrent use of intravenous diuretics, digoxin, or QT prolonging drugs exhibited lower risk of TdP.

[Cardiac arrhythmias in adults with congenital heart disease]. / Herzrhythmusstörungen bei Erwachsenen mit angeborenen Herzfehlern.

In patients with congenital heart disease, cardiac arrhythmias are complex and require a thorough understanding of the anatomy, past surgical and interventional procedures, and the specific electric processes. Supraventricular tachycardias commonly present as emergency situations and should be treated immediately, particularly when there is an underlying complex malformation. Establishing sinus rhythm is usually superior to pure frequency control for hemodynamic reasons. Catheter ablation should be preferred over medical treatment, even though several procedures are often necessary. In addition, bradycardia is seen more frequently in congenital heart defects; this could be aggravated by antiarrhythmic drugs. There are significant differences between the indications and techniques used for pacemaker implantation in patients with congenital heart defects and those without. Patients with complex congenital heart diseases have an increased risk of thromboembolism; therefore, an individual and early indication for low-threshold oral anticoagulation is necessary; direct oral anticoagulants can also be used for this purpose. In risk stratification for sudden cardiac death, the principles of general guidelines are often not applicable, and individualized decisions are required. Recently, a new general risk score for congenital heart disease has been developed. The treatment of cardiac arrhythmias in patients with congenital heart disease should always be performed in close cooperation with specialized centers.

Blunted tachycardia and cardiac sympathetic denervation in isolated rapid eye movement sleep behavior disorder.

BACKGROUND: Isolated rapid eye movement sleep behavior disorder (iRBD) serves as a prodromal phase of Parkinson's disease (PD) and dementia with Lewy bodies (DLB). Blunted tachycardia (BT) during postural changes indicates neurogenic orthostatic hypotension, a marker of autonomic dysfunction. We aimed to investigate whether BT is associated with cardiac sympathetic neurogenic denervation. Additionally, we conducted a preliminary short-term follow-up to examine the potential prognostic significance of BT regarding phenoconversion and mortality. METHODS: Forty-three patients with iRBD at Shiga University of Medical Science Hospital underwent active standing tests to identify BT, defined by a specific ratio of decrease in systolic blood pressure to inadequate increase in heart rate after standing, and orthostatic hypotension. 123I-metaiodobenzylguanidine myocardial scintigraphy (123I-MIBG) and dopamine transporter single-photon emission computed tomography (DAT-SPECT) were performed. Participants were followed up for 3.4 ± 2.4 years for phenoconversion and 4.0 ± 2.3 years for mortality assessment, and the risk of events was analyzed using log-rank tests. RESULTS: Among the 43 participants (mean age, 72.3 ± 7.9 years; 8 female), 17 met the BT criteria. We found no significant comorbidity-related differences in hypertension or diabetes between the BT(+) and BT(-) groups. Orthostatic hypotension was more prevalent in the BT(+) group than in the BT(-) group (47.1% vs 7.7%, p = 0.003). BT(+) patients were older with a lower early and delayed MIBG uptake; however, no significant differences were observed in DAT accumulation. Phenoconversion was observed in seven (41.2%) BT(+) and seven (26.9%) BT(-) patients. Three deaths were recorded in the BT(+) group (17.6%) and three in the BT(-) group (11.5%). No significant differences were observed in the risk of phenoconversion or mortality between the groups. CONCLUSIONS: We have identified the possibility that BT reflects cardiac sympathetic neurogenic denervation in patients with iRBD. Future research is needed to elucidate the potential prognostic value of BT.

Can I Discharge This Adult Patient with Abnormal Vital Signs From the Emergency Department?

BACKGROUND: Vital signs are an essential component of the emergency department (ED) assessment. Vital sign abnormalities are associated with adverse events in the ED setting and may indicate a risk of poor outcomes after ED discharge. CLINICAL QUESTION: What is the risk of adverse events among adult patients with abnormal vital signs at the time of ED discharge? EVIDENCE REVIEW: Studies retrieved included 6 retrospective studies with adult patients discharged from the ED. These studies evaluated adverse outcomes in adult patients discharged from the ED with abnormal vital signs. Hypotension at discharge was associated with the highest odds of adverse events after discharge. Tachycardia was also a key predictor of adverse events after discharge and may be easily missed by ED clinicians. CONCLUSION: Based on the available evidence, the specific vital sign abnormality and the number of total abnormalities influence the risk of adverse outcomes after discharge. Vital sign abnormalities at the time of discharge also increase the risk of ED revisit. The most common abnormal vital sign at the time of discharge is tachycardia.

Idiopathic Ventricular Fibrillation - Just How Much Idiopathic is it?

Idiopathic ventricular fibrillation is diagnosed in survivors of sudden cardiac death that has been caused by ventricular fibrillation without known structural or electrical abnormalities, even after extensive investigation. It is a common cause of sudden death in young adults. Although idiopathic ventricular fibrillation is a diagnosis of exclusion, in many cases only a partial investigation algorithm is performed. The aim of this review is to present a comprehensive diagnostic evaluation algorithm with a focus on diagnostic assessment of inherited arrhythmic syndromes and genetic background.

Excess of high-caffeinated energy drinks causing ventricular arrhythmias.

A young male patient had palpitations after consumption of few high caffeinated energy drinks which he took after his office hours to relieve fatigue. He immediately seeked medical help. Electrocardiogram showed multiple runs of non-sustained ventricular tachycardia and ventricular bigeminy and trigeminy. Echocardiography was normal. The patient was admitted to intensive care unit and treated with anti-arrhythmic drugs to which the arrhythmias responded and subsided. Cardiac magnetic resonance imaging of heart did not reveal any structural heart abnormality and treadmill stress test was negative ruling out significant coronary artery disease. High caffeinated energy drinks can produce serious ventricular arrhythmias if taken beyond safe doses. These ventricular arrhythmias are known to be causative factor for sudden cardiac arrest and therefore a caution & regulation is needed in widespread unrestricted used of these drinks.

Long-term outcomes of ventricular tachycardia ablation in repaired tetralogy of Fallot: Systematic review and meta-analysis.

Background: Ventricular tachycardia (VT) remains a risk in repaired Tetralogy of Fallot (rTOF); however, long-term benefits of VT ablation have not been established. This study compares the outcomes of rTOF patients with and without VT ablation. Methods: We searched multiple databases examining the outcomes of rTOF patients who had undergone VT ablation compared to those without ablation. Primary outcomes were VT recurrence, sudden cardiac death (SCD), and all-cause mortality. Subgroup analysis was conducted based on the type of ablation (catheter and surgical). Slow-conducting anatomical isthmus (SCAI)-based catheter ablation (CA) was also analyzed separately. The secondary outcome was the risk factors for the pre-ablation history of VT. Results: Fifteen cohort studies with 1459 patients were included, 21.4% exhibited VTs. SCAI was found in 30.4% of the population, with 3.7% of non-inducible VT. Factors significantly associated with VT before ablation included a history of ventriculostomy, QRS duration ≥180 ms, fragmented QRS, moderate to severe pulmonary regurgitation, high premature ventricular contractions burden, late gadolinium enhancement, and SCAI. Ablation was only beneficial in reducing VTs recurrence in SCAI-based CA (risk ratio (RR) 0.11; 95% CI 0.03 to 0.33. p < 0.001; I2 = 0%) with no recurrence in patients with preventive ablation (mean follow-up time 91.14 ± 77.81 months). The outcomes of VT ablation indicated a favorable trend concerning SCD and all-cause mortality (RR 0.49 and 0.44, respectively); however, they were statistically insignificant. Conclusions: SCAI-based CA has significant advantages in reducing VT recurrence in rTOF patients. Risk stratification plays a key role in determining the decision to perform ablation.

SVT quest: The adventure diagnosing narrow QRS tachycardia.

In the field of cardiac electrophysiology, there is a universal desire: the discovery of a flawless diagnostic maneuver for supraventricular tachycardias (SVTs). This is not merely a wish but a shared odyssey. To improve diagnostic accuracy and achieve sufficient sensitivity and specificity, numerous diagnostic maneuvers have been proposed. However, each has its limitations and prompts a search for new diagnostic techniques. This continuous cycle of discovery and refinement, which we titled "SVT Quest" is reviewed in chronological sequence. This adventure in diagnosing narrow QRS tachycardia unfolds in 3 steps: Step 1 involves differentiating atrial tachycardia from other SVTs based on the observations such as V-A-V or V-A-A-V response, ΔAA interval, VA linking, the last entrainment sequence, and response to the atrial extrastimulus. Step 2 focuses on differentiating orthodromic reciprocating tachycardia from atrioventricular nodal reentrant tachycardia based on the observations such as tachycardia reset upon the premature ventricular contraction during His refractoriness, uncorrected/corrected postpacing interval, differential ventricular entrainment, orthodromic His capture, transition zone analysis, and total pacing prematurity. Step 3 characterizes the concealed nodoventricular/nodofascicular pathway and His-ventricular pathway-related tachycardia based on observations such as V-V-A response, ΔatrioHis interval, and paradoxical reset phenomenon. There is no single diagnostic maneuver that fits all scenarios. Therefore, the ability to apply multiple maneuvers in a case allows the operator to accumulate evidence to make a likely diagnosis. Let's embark on this adventure!

Tachycardia with cycle length alternans in Ebstein's anomaly.

The tachycardia which presents with regularly irregular rhythm consists of a broad set of differential diagnoses. We present a case of cycle length alternans tachycardia in a patient, with Ebstein's anomaly and describe how a diagnosis was arrived at after careful analysis of electrocardiogram and EGMs.

A case of a permanent form of junctional reciprocating tachycardia with negative linking on atrial differential pacing.

This case of PJRT shows negative linking on ventriculoatrial intervals after atrial differential pacing. Interpreting the results of atrial differential pacing may be challenging in cases where the pacing site affects retrograde conduction or when retrograde conduction is unstable.

Cardiac sympathetic denervation for catecholaminergic polymorphic ventricular tachycardia in the light of the medical situation in Japan.

Progress of treadmill exercise testing in Case 1 Each electrocardiogram shows the maximum load. Before left cardiac sympathetic denervation, polymorphic ventricular tachycardias were observed. After left cardiac sympathetic denervation, no ventricular arrhythmias were induced during exercise.

Spatial analysis and characteristics of persistent late potentials after ablation of scar-related VT substrate- implications for late potential elimination as a procedural endpoint with high-resolution mapping.

BACKGROUND: Late potential elimination has been proposed as a surrogate endpoint for scar-related VT ablation procedures. The characteristics, distribution, and predictors of persistent LPs (pLP) after ablation have not been studied. OBJECTIVE: We sought to characterize the spatial distribution and features of pLP after catheter ablation of VT substrate with high-resolution mapping. METHODS: Cases of scar-related VT ablation with adequate pre- and post-ablation electroanatomical maps (EAM) acquired exclusively using a high-density grid (HDG) catheter were reviewed from 2021-2023. RESULTS: A total of 62 EAM (pre- and post-ablation) from 31 cases using HDG were reviewed. Persistent late potentials (pLP) were observed in 19 cases after ablation (61%). New LP, spatially distinct from pre-ablation LP, at the periphery of the ablation area comprised the majority of pLP (16/19, 84%). Isolated pLP were more prevalent than fractionated pLP with a median amplitude of 0.26mV (0.09-0.59mV). The presence of pLP was associated with a significantly lower LVEF and septal ablation but not low voltage, late potential, or ablation area as compared to absence of pLP (22.8±7.8% vs 31.5±8.0% [p =0.008] for LVEF, and 83% vs 44% [p = 0.033] for septal ablation). CONCLUSIONS: Formation of spatially distinct new LP after targeted VT ablation is common especially in patients with lower LVEF and septal substrate independent of ablation burden. This finding highlights the limitations of complete LP elimination as an endpoint to VT ablation procedures.

Gastroesophageal reflux disease and risk for arrhythmias: a Mendelian randomization analysis.

Background: Clinical observations and epidemiological studies suggest a potential linkage between gastroesophageal reflux disease (GERD) and arrhythmias, yet the underlying mechanism remains elusive. This study investigates the causal relationship between GERD and four types of arrhythmia through a genetic lens, employing Mendelian randomization analysis to elucidate the directionality of these associations. Methods: Selected single nucleotide polymorphisms (SNPs) from genome-wide association study (GWAS) data were utilized as instrumental variables. The inverse variance weighting (IVW) method, MR-Egger regression analysis, and the weighted median method were employed in two-sample Mendelian randomization analysis. Horizontal pleiotropy was detected and corrected using the MR-PRESSO test and MR-Egger regression. The stability and reliability of the Mendelian randomization results were assessed using the leave-one-out method, Cochran's Q test, and funnel plots. The causal relationship between GERD and four types of arrhythmias was evaluated using the odds ratio (OR). Results: IVW results indicated that GERD could increase the risk of arrhythmias. A one standard deviation increases in the logarithmically transformed GERD score resulted in a 34% increase in the risk of arrhythmia (OR = 1.34; 95% CI 1.19-1.51; p = 1.66E-06). No significant correlation was found between GERD and other arrhythmias. Conclusion: A causal relationship exists between GERD and arrhythmias, suggesting that GERD increases the risk of developing these arrhythmias.

Titin Cardiomyopathy Associated With Refractory Ventricular Tachycardia: A Case Report.

Cardiomyopathy is defined as structural and functional myocardial abnormality not attributed to ischemic, valvular, hypertensive, or congenital cardiac causes. The main phenotypes of cardiomyopathy include hypertrophic, dilated, non-dilated left ventricular, restrictive, arrhythmogenic right ventricular, Takotsubo, and left ventricular noncompaction cardiomyopathies. A significant proportion of dilated cardiomyopathy (DCM) cases represents patients with genetic mutations, most commonly titin gene truncating variants (TTNtv). It has been shown that TTNtv mutation contributes to the development of certain types of DCM such as alcohol, chemotherapy, and peripartum. We present a case of DCM where genetic workup revealed TTNtv without other contributing factors. The course was complicated by multiple ventricular tachycardias (VTs) refractory to medical management, despite treatment with amiodarone, sotalol, dofetilide, mexiletine, and propranolol. Interestingly, endocardial mapping failed to delineate the substrate of tachycardia. This report underscores the importance of genetic testing in DCM and highlights the potential association of titin cardiomyopathy with refractory VTs, possibly of epicardial origin.

Electroporation saves the day again: Pulsed-field ablation for phrenic nerve-sparing in right atrial tachycardia.

INTRODUCTION: Pulsed-field ablation (PFA) is a novel nonthermal energy that shows unique features that can be of use beyond pulmonary vein ablation, like tissue selectivity or proximity rather than contact dependency. METHODS AND RESULTS: We report three cases of right focal atrial tachycardias arising from the superior cavoatrial junction and the crista terminalis, in close relationship with the phrenic nerve, effectively ablated using a commercially available PFA catheter designed for pulmonary vein isolation without collateral damage. CONCLUSION: PFA can be useful for treating right atrial tachycardias involving sites near the phrenic nerve, avoiding the need for complex nerve-sparing strategies.