Hypokalemia unmasking underlying premature ventricular contraction induced polymorphic ventricular tachycardia: Low potassium is not always the culprit!

Hypokalemia is prevalent in patients resuscitated from out-of-hospital cardiac arrest and can contribute to polymorphic ventricular tachycardia (PMVT) by prolonging the QT interval. We present an interesting scenario of malignant ventricular arrythmia initially attributed to moderate hypokalemia that persisted after correction of potassium. Subsequent electrophysiological study showed two frequent PMVT-triggering PVCs mapped to the base of the antero-lateral papillary muscle and the para-Hisian region of the right side of the interventricular septum. The patient underwent catheter ablation to prevent further recurrences and dual chamber ICD implantation for secondary prevention.

Portomesenteric venous thrombosis after laparoscopic sleeve gastrectomy: A case report and a call for prevention.

Postoperative portomesenteric venous thrombosis (PMVT) is being increasingly reported after bariatric surgery. It is variable and often a nonspecific presentation along with its potential for life-threatening and life-altering outcomes makes it imperative that it is prevented, detected early and treated optimally. We report the case of a 50-year-old morbidly obese man undergoing a laparoscopic sleeve gastrectomy who developed symptomatic PMVT two weeks postsurgery, which was successfully treated by anticoagulant therapy. We provide postulates to the etiopathological mechanism for this thrombotic entity. The growing recognition that obesity and bariatric surgery create a procoagulant state regionally and systemically provides impetus for designing the ideal protocol for PMVT prophylaxis, which could be more common than currently believed. We support the early screening for PMVT in the postbariatric surgical patient with unexplainable or intractable abdominal symptoms. The role of routine surveillance and the ideal duration of post-PMVT anticoagulation is yet to be elucidated.

Transjugular intrahepatic portosystemic shunt combined with dual-access thrombolysis for acute severe non-cirrhotic portal-mesenteric vein thrombosis.

OBJECTIVE: Non-cirrhotic porto-mesenteric vein thrombosis (NC-PMVT) is a rare but severe clinical condition. The study aims to assess the effectiveness and safety of transjugular intrahepatic portosystemic shunt (TIPS) coupled with dual-access thrombolysis in patients with acute severe NC-PMVT. METHODS: From January 2018 to February 2023, a total of 25 patients with acute severe NC-PMVT who were treated with TIPS in conjunction with mechanical thrombectomy and dual-access thrombolysis. The period of thrombolysis was determined by the improvement of clinical symptoms and vascular recanalization. The technical success, recanalization rate, clinical success, and procedure-related complications were analyzed. RESULTS: The technical success rate was 100 %. The median duration for thrombolytic catheter removal was 5 (IQR 3.5 - 7) days. Full and partial recanalization were accomplished in 10 (40 %) and 15 (60 %) patients respectively before discharge. No significant procedure-related complications were reported. The clinical success rate was 88 %, with a mortality rate of 12 %. Over a median follow-up of 8 months, 3/22 (13.64 %) patients had a recurrence of thrombosis; 1/22 (4.54 %) patients underwent partial intestinal resection one and a half months post-discharge; the remaining patients did not experience any portal hypertensive complications. CONCLUSION: The combination of TIPS and dual-access thrombolysis appears to be safe and effective for patients with acute severe NC-PMVT.

Personalized medicine in the dish to prevent calcium leak associated with short-coupled polymorphic ventricular tachycardia in patient-derived cardiomyocytes.

BACKGROUND: Polymorphic ventricular tachycardia (PMVT) is a rare genetic disease associated with structurally normal hearts which in 8% of cases can lead to sudden cardiac death, typically exercise-induced. We previously showed a link between the RyR2-H29D mutation and a clinical phenotype of short-coupled PMVT at rest using patient-specific hiPSC-derived cardiomyocytes (hiPSC-CMs). In the present study, we evaluated the effects of clinical and experimental anti-arrhythmic drugs on the intracellular Ca2+ handling, contractile and molecular properties in PMVT hiPSC-CMs in order to model a personalized medicine approach in vitro. METHODS: Previously, a blood sample from a patient carrying the RyR2-H29D mutation was collected and reprogrammed into several clones of RyR2-H29D hiPSCs, and in addition we generated an isogenic control by reverting the RyR2-H29D mutation using CRIPSR/Cas9 technology. Here, we tested 4 drugs with anti-arrhythmic properties: propranolol, verapamil, flecainide, and the Rycal S107. We performed fluorescence confocal microscopy, video-image-based analyses and biochemical analyses to investigate the impact of these drugs on the functional and molecular features of the PMVT RyR2-H29D hiPSC-CMs. RESULTS: The voltage-dependent Ca2+ channel inhibitor verapamil did not prevent the aberrant release of sarcoplasmic reticulum (SR) Ca2+ in the RyR2-H29D hiPSC-CMs, whereas it was prevented by S107, flecainide or propranolol. Cardiac tissue comprised of RyR2-H29D hiPSC-CMs exhibited aberrant contractile properties that were largely prevented by S107, flecainide and propranolol. These 3 drugs also recovered synchronous contraction in RyR2-H29D cardiac tissue, while verapamil did not. At the biochemical level, S107 was the only drug able to restore calstabin2 binding to RyR2 as observed in the isogenic control. CONCLUSIONS: By testing 4 drugs on patient-specific PMVT hiPSC-CMs, we concluded that S107 and flecainide are the most potent molecules in terms of preventing the abnormal SR Ca2+ release and contractile properties in RyR2-H29D hiPSC-CMs, whereas the effect of propranolol is partial, and verapamil appears ineffective. In contrast with the 3 other drugs, S107 was able to prevent a major post-translational modification of RyR2-H29D mutant channels, the loss of calstabin2 binding to RyR2. Using patient-specific hiPSC and CRISPR/Cas9 technologies, we showed that S107 is the most efficient in vitro candidate for treating the short-coupled PMVT at rest.

Primary Catheter-Directed Thrombolysis for Porto-Mesenteric Venous Thrombosis (PMVT) in Non-Cirrhotic Patients.

Purpose: To report our thrombolytic technique, treatment strategy, and clinical outcomes for porto-mesenteric venous thrombosis (PMVT) in non-cirrhotic patients. Methods: Sixteen acute or chronic non-cirrhotic PMVT patients (mean age: 48.6 years) with imminent intestinal ischemia were enrolled from 2004 to 2020. Eight patients presented thrombus extension into the peripheral mesenteric vein, close to the venous arcade. Transhepatic catheter-directed thrombolysis (CDT) was performed by urokinase infusion (60,000-30,000 IU/h concomitant with heparin 300-400 IU/h), catheter aspiration, and/or balloon dilation/stent placement. Additional intra-arterial mesenteric infusion of urokinase (30,000 IU/h) was given in patients with the peripheral mesenteric venules involved. Transjugular intrahepatic porto-systemic shunt (TIPS) was created in patients with poor recanalization of the intrahepatic portal flow (PV). Results: The transhepatic route was adopted in all patients, with adjunct indirect mesenteric arterial thrombolytic infusion in eight patients. A total of up to 20.4 million IU urokinase was infused for 1-21 days' treatment duration. TIPS was created in three patients with recanalization failure of the intrahepatic PV. Technical success was achieved in 100% of patients with complete recanalization of 80% and partial recanalization of 20%. No major procedure-related complications were encountered. The 30-day mortality rate was 6.7%. The overall two-year primary patency was 84.6%. Conclusions: CDT can be performed as a primary salvage treatment once the diagnosis is made. CDT via the transhepatic route with tailored thrombolytic regimen is safe and effective for both acute and chronic PMVT. TIPS creation can be preserved in non-cirrhotic PMVT patients if intrahepatic PV recanalization fails.

Termination of Sustained Ventricular Fibrillation During Radiofrequency Catheter Ablation.

After a ST-segment elevation inferior myocardial infarction, a patient developed multiple drug-refractory ventricular fibrillation (VF), triggered by a stereotypic premature ventricular complex. During an episode of sustained VF, catheter ablation of the moderator band terminated VF, with transition into monomorphic ventricular tachycardia. To the best of our knowledge, this is the first-in-human report of termination of VF during delivery of radiofrequency energy, which suggests that the focal area on moderator band of Purkinje system had an active role in the perpetuation of VF. (Level of Difficulty: Advanced.).

Refractory Ventricular Tachycardia Originating From an Intracardiac Metastasis Treated With Catheter Ablation.

A 45-year-old man with stage IV melanoma presented with incessant nonsustained wide complex tachycardia. He was found to have a right ventricular intracardiac metastasis that created a nidus for ventricular tachycardia refractory to multiple therapeutic interventions. The patient underwent catheter ablation for this rare indication, with successful arrhythmia control by direct ablation over the tumor surface. (Level of Difficulty: Advanced.).

Modeling polymorphic ventricular tachycardia at rest using patient-specific induced pluripotent stem cell-derived cardiomyocytes.

BACKGROUND: While mutations in the cardiac type 2 ryanodine receptor (RyR2) have been linked to exercise-induced or catecholaminergic polymorphic ventricular tachycardia (CPVT), its association with polymorphic ventricular tachycardia (PMVT) occurring at rest is unclear. We aimed at constructing a patient-specific human-induced pluripotent stem cell (hiPSC) model of PMVT occurring at rest linked to a single point mutation in RyR2. METHODS: Blood samples were obtained from a patient with PMVT at rest due to a heterozygous RyR2-H29D mutation. Patient-specific hiPSCs were generated from the blood samples, and the hiPSC-derived cardiomyocytes (CMs) were generated via directed differentiation. Using CRIPSR/Cas9 technology, isogenic controls were generated by correcting the RyR2-H29D mutation. Using patch-clamp, fluorescent confocal microscopy and video-image-based analysis, the molecular and functional properties of RyR2-H29D hiPSCCMs and control hiPSCCMs were compared. FINDINGS: RyR2-H29D hiPSCCMs exhibit intracellular sarcoplasmic reticulum (SR) Ca2+ leak through RyR2 under physiological pacing. RyR2-H29D enhances the contribution of inositol 1,4,5-trisphosphate receptors to excitation-contraction coupling (ECC) that exacerbates abnormal Ca2+ release in RyR2-H29D hiPSCCMs. RyR2-H29D hiPSCCMs exhibit shorter action potentials, delayed afterdepolarizations, arrhythmias and aberrant contractile properties compared to isogenic controls. The RyR2-H29D mutation causes post-translational remodeling that is fully reversed with isogenic controls. INTERPRETATION: To conclude, in a model based on a RyR2 point mutation that is associated with short-coupled PMVT at rest, RyR2-H29D hiPSCCMs exhibited aberrant intracellular Ca2+ homeostasis, shortened action potentials, arrhythmias and abnormal contractile properties. FUNDING: French Muscular Dystrophy Association (AFM; project 16,073, MNM2 2012 and 20,225), "Fondation de la Recherche Médicale" (FRM; SPF20130526710), "Institut National pour la Santé et la Recherche Médicale" (INSERM), National Institutes of Health (ARM; R01 HL145473) and New York State Department of Health (NYSTEM C029156).

Portomesenteric Vein Thrombosis after Laparoscopic Sleeve Gastrectomy: A Case Report.

Portomesenteric vein thrombosis is an uncommon but potentially life-threatening complication associated with laparoscopic sleeve gastrectomy. We present the case of a 26-year-old male who underwent an uneventful laparoscopic sleeve gastrectomy and presented on postoperative day 14 with portomesenteric vein thrombosis. The patient was treated conservatively with IV heparinization, followed by an oral anticoagulant agent. He was discharged in stable condition without further problems. A high index of suspicion for the disease is required not to miss or delay the diagnosis of portomesenteric vein thrombosis which could lead to a fatal outcome. All patients should be screened beforehand for underlying hypercoagulability before surgery.

Electrical Storm in COVID-19.

COVID-19 is a global pandemic caused by SARS-CoV-2. Infection is associated with significant morbidity and mortality. Individuals with pre-existing cardiovascular disease or evidence of myocardial injury are at risk for severe disease and death. Little is understood about the mechanisms of myocardial injury or life-threatening cardiovascular sequelae. (Level of Difficulty: Intermediate.).

Catecholaminergic polymorphic ventricular tachycardia: An exciting new era.

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a highly malignant inheritable cardiac channelopathy. The past decade and a half has provided exciting new discoveries elucidating the genetic etiology and pathophysiology of CPVT. This review of the current literature on CPVT aims to summarize the state of the art in our understanding of the genetic etiology and the molecular pathogenesis of CPVT, and how these relate to our current approach to diagnosis and management. We will also shed light on groundbreaking new work that will continue to refine the management of CPVT in the future. As our knowledge of CPVT continues to grow, further studies will yield a better understanding of the efficacy and pitfalls of established diagnostic approaches and therapies as well as help shape newer diagnostic and treatment strategies. Two separate searches were run on the National Center for Biotechnology Information's (NCBI) website. The first used the medical subject headings (MeSH) database using the term "catecholaminergic polymorphic ventricular tachycardia" that was run on the PubMed database using the age filter (birth to 18 years), and it yielded 58 results. The second search using the MeSH database with the search term "catecholaminergic polymorphic ventricular tachycardia," applying no filters yielded 178 results. The abstracts of all these articles were studied and the articles were categorized and organized. Articles of relevance were read in full. As and where applicable, relevant references and citations from the primary articles were further explored and read in full.

Wearable cardioverter-defibrillator use in patients perceived to be at high risk early post-myocardial infarction.

OBJECTIVES: The aim of this study was to describe usage of the wearable cardioverter-defibrillator (WCD) during mandated waiting periods following myocardial infarction (MI) for patients perceived to be at high risk for sudden cardiac arrest (SCA). BACKGROUND: Current device guidelines and insurance coverage require waiting periods of either 40 days or 3 months before implanting a cardioverter-defibrillator post-myocardial infarction (MI), depending on whether or not acute revascularization was undertaken. METHODS: We assessed characteristics of and outcomes for patients who had a WCD prescribed in the first 3 months post-MI. The WCD medical order registry was searched for patients who were coded as having had a "recent MI with ejection fraction ≤35%" or given an International Classification of Diseases, Ninth Revision 410.xx diagnostic code (acute MI), and then matched to device-recorded data. RESULTS: Between September 2005 and July 2011, 8,453 unique patients (age 62.7 ± 12.7 years, 73% male) matched study criteria. A total of 133 patients (1.6%) received 309 appropriate shocks. Of these patients, 91% were resuscitated from a ventricular arrhythmia. For shocked patients, the left ventricular ejection fraction (LVEF) was ≤30% in 106, 30% to 35% in 17, >36% in 8, and not reported in 2 patients. Of the 38% of patients not revascularized, 84% had a LVEF ≤30%; of the 62% of patients revascularized, 77% had a LVEF ≤30%. The median time from the index MI to WCD therapy was 16 days. Of the treated patients, 75% received treatment in the first month, and 96% within the first 3 months of use. Shock success resulting in survival was 84% in nonrevascularized and 95% in revascularized patients. CONCLUSIONS: During the 40-day and 3-month waiting periods in patients post-MI, the WCD successfully treated SCA in 1.4%, and the risk was highest in the first month of WCD use. The WCD may benefit individual patients selected for high risk of SCA early post-MI.

Survival after shock therapy in implantable cardioverter-defibrillator and cardiac resynchronization therapy-defibrillator recipients according to rhythm shocked. The ALTITUDE survival by rhythm study.

OBJECTIVES: This study sought to determine if the risk of mortality associated with inappropriate implantable cardioverter-defibrillator (ICD) shocks is due to the underlying arrhythmia or the shock itself. BACKGROUND: Shocks delivered from ICDs are associated with an increased risk of mortality. It is unknown if all patients who experience inappropriate ICD shocks have an increased risk of death. METHODS: We evaluated survival outcomes in patients with an ICD and a cardiac resynchronization therapy defibrillator enrolled in the LATITUDE remote monitoring system (Boston Scientific Corp., Natick, Massachusetts) through January 1, 2010. First shock episode rhythms from 3,809 patients who acutely survived the initial shock were adjudicated by 7 electrophysiologists. Patients with a shock were matched to patients without a shock (n = 3,630) by age at implant, implant year, sex, and device type. RESULTS: The mean age of the study group was 64 ± 13 years, and 78% were male. Compared with no shock, there was an increased rate of mortality in those who received their first shock for monomorphic ventricular tachycardia (hazard ratio [HR]: 1.65, p < 0.0001), ventricular fibrillation/polymorphic ventricular tachycardia (HR: 2.10, p < 0.0001), and atrial fibrillation/flutter (HR: 1.61, p = 0.003). In contrast, mortality after first shocks due to sinus tachycardia and supraventricular tachycardia (HR: 0.97, p = 0.86) and noise/artifact/oversensing (HR: 0.91, p = 0.76) was comparable to that in patients without a shock. CONCLUSIONS: Compared with no shock, those who received their first shock for ventricular rhythms and atrial fibrillation had an increased risk of death. There was no significant difference in survival after inappropriate shocks for sinus tachycardia or noise/artifact/oversensing. In this study, the adverse prognosis after first shock appears to be more related to the underlying arrhythmia than to an adverse effect from the shock itself.