Restoration Of Sinus Rhythm Research Articles

892 ELECTRICAL STORM IN ISCHAEMIC HEART DISEASE: A CASE OF LEFT STELLATE GANGLION BLOCK AS BRIDGE TO URGENT PCI RESCUE

Abstract A 73 year-old man was admitted for syncope and sustained ventricular arrhythmia complicated by cardiogenic shock treated with electrical cardioversion and restoration of sinus rhythm. Former smoker, he suffered by arterial hypertension, hypercholesterolemia and known heart failure with reduced ejection fraction. In the 1995 the patient underwent aortic valve replacement surgery with a mechanical prosthetic valve. The patient underwent coronary angiography that showed multivessel coronary artery disease with functional occlusion of posterior interventricular artery (rehabilitated by hetero-coronary circles) and critical stenosis of the middle left anterior descending artery. In this angiographic framework, the indication was collegial revaluation considering other patient's comorbidities (chronic renal dysfunction, mitral moderate-severe regurgitation). The patient underwent ICD implantation for secondary prevention. Despite maximal medical therapy, the patient experienced new episodes of sustained VT complicated by hemodynamic instability. Hypokalemia, hypomagnesemia and hyperthyroidism were excluded as triggering factors for arrhythmias on laboratory investigations. In the following days due to persistent and symptomatic arrhythmias, configuring electrical storm, we decided to proceed with anatomical stellate ganglion block, guarantying a free interval from ventricular arrhythmia about six hours. The anesthetic has been injected at the C6 or C7 vertebral level with the Chassignac's tubercle, the cricoid cartilage, and the carotid artery serving as the anatomic landmarks to the procedure. An aspiration test must be done to avoid the suction of blood or cerebrospinal fluid, then a local anesthetic is injected, and the diffusion of the injectate is seen in real-time. Local anesthetic (lidocaine mixed with bupivacaine) is injected until the fluid spread along the paravertebral fascia to the stellate ganglion. The period free from VA allowed us to transfer the patient in another center in order to receive myocardial revascularization supported by ECMO. Left ganglion stellate block has a central role in the treatment of the refractory ventricular arrhythmias and may offer effective arrhythmia control giving time to rescue and/or other bridge therapy. In our case, it had a key role to perform an inter-hospital transfer and subsequent “rescue PCI therapy”. Thanks to Stellate ganglion block, the sinus rhythm was retained immediately, there were no ventricular tachycardia episodes for at least six hours allowing to perform myocardial revascularization supported by ECMO. No further ventricular arrhythmias occurred after revascularization, corroborating the ischemic trigger of electrical storm.

178 ARRHYTHMIC STORM IN ATTR WILD TYPE AMYLOIDOSIS: AN UNUSUAL COMBINATION

Abstract Cardiac amyloidosis (CA) is characterized by extracellular protein fibril deposition in the myocardium leading to restrictive heart failure. Both atrial and ventricular arrhythmias are common in CA. Study have shown up to one half of patients with CA die suddenly. However, the most common cause of sudden death has been historically through to be secondary electromechanical dissociation rather than a lethal ventricular arrhythmia. We present the case of a 84 years old man, with a history of hypertension, dyslipidaemia, and prior smoking. In June 2020 the patient was admitted to the emergency room of our hospital due to an episode of hemodynamically unstable sustained ventricular tachycardia (SVT). The patient underwent electrical cardioversion with restoration of sinus rhythm. An echocardiogram that showed a slightly reduced ejection fraction (FE = 45%), severe concentric hypertrophy, grade 3 diastolic dysfunction with high pressures in the left ventricular (LV) cavity, and a reduced GLS (-13.8%) with a typical apical-sparing aspect. A cardiac magnetic resonance (Fig.1). was performed showing a diffuse area of LGE with a subepicardial pattern involving left ventricular and atrial segments, compatible with myocardial storage disease. In order to complete the diagnostic workout, we performed a bone scintigraphy (Fig.2). (Positive for CA, with Perugini score grade 2), a genetic test (negative for hATTR-CA mutations) and free light chain in serum (negative for AL-CA). The patient was discharged at home after ICD implantation in secondary prevention and prescribed appropriate heart failure therapy. In May 2022 the patient was readmitted in emergency room for dyspnea during an arrhythmic storm characterized by several SVTs and ICD interventions, and atrial fibrillation (FA). After stabilization of clinical parameters, the patient was hospitalized in our ward. We optimized medical therapy with metaprololo 100 mg 1 cp BID, cordarone 600 mg ev and mexiletina 200 mg cp BID. During the hospitalization we succeeded in reducing SVT burden. However, ventricular PVCs and slow SVT remained. For this reason, we decided to perform an electrophysiological study (EPS) followed by catheter ablation. The EPS found two low voltage areas (Fig.3). The first were found under the aortic valve; the second was an area of dense scar and fragmented potentials along the basal-posterior wall. After ablation of the first area we succeeded in removing clinical PVCs. During the ablation of the second area the procedure was complicated by ventricular fibrillation that required advanced life support and many electrical shocks. The patient was discharged at home in absence of further episodes of SVTs with optimized therapy At a three moths follow up no arrhythmic events were recorded.

230 ANOMALOUS ORIGIN OF LEFT CIRCUMFLEX ARTERY FROM RIGHT SINUS OF VALSALVA: A RARE CASE BUT WITH GREAT CLINICAL RELEVANCE

Abstract Introduction The anomalous connection of the left circumflex artery (LCx) to the right coronary artery (RCA) or sinus is the most frequent coronary artery (CA) anomaly. Among them, only those with an interarterial course are regarded as hidden conditions at risk of myocardial ischemia (MI) and sudden cardiac death (SCD). We report an uncommon of anomalous origin of LCx from the right sinus of Valsalva and a retroaortic path causing MI. Case presentation A 61-year-old man presented to the emergency department complaining palpitations and chest discomfort for an hour. He only had history of hypertension. Physical examination was unremarkable. The ECG demonstrated atrial flutter with a 2:1 conduction ratio and a ventricular rate of 157 bpm and ST segment depression in leads V4-6. Transthoracic echocardiography did not reveal segmental kinetic anomalies but a five-chamber apical view showed a “RAC sign”, typical of anomalous retroaortic course of the left coronary artery. The patient was treated with intravenous infusion of amiodarone. He restored sinus rhythm and symptoms regressed completely, but the ECG taken after conversion showed flattened T waves in leads V5-6 and negative T waves in I and aVL. Cardiac enzymes had transient increase. After the acute episode ended the patient underwent cardiac computed tomography angiography (CTA) with evidence of anomalous origin of LCx from the right sinus with a retroaortic course. A coronary angiography excluded obstructive atherosclerotic coronary lesions. Nuclear myocardial perfusion imaging revealed reversible small subsegmental perfusion defects in mid inferolateral wall and apical lateral wall. We established a medical treatment with beta-blocker. Discussion Our patient had anomalous connection of the LCx branch to the right sinus of Valsalva with a retroaortic course. Although this anomaly is usually considered benign, cases of association with SCD and MI have been reported. The factor responsible for this pathogenicity could be high orifice, ostial stenosis, slit-like/fish-mouth-shaped orifice and acute-angle take-off. As cardiac CTA did not reveal any of these characteristics, we hypothesized that the increased cardiac output and expansion of the great vessels during tachycardia could cause compression of the retroaortic segment or angling at its origin and generate ischemia. Repolarization abnormalities at ECG are well documented during supraventricular tachycardia as a response to pacing-induced stress. These changes are usually diffused and disappear after conversion to sinus rhythm. In this case they appeared hours later, accompanied by cardiac enzyme buildup. As the epicardial coronary arteries did not show any pathology, we suggest that the patient had transient ischemia due to LCx anomaly. We confirmed it by myocardial perfusion imaging. As for the management of this anomaly in adults, surgery is recommended as class IC in patients with typical angina symptoms who present with evidence of stress-induced myocardial ischemia in a matching territory or high-risk anatomy. Our patient has never had clear manifestations of angina. All these elements together with the age of our patient motivated us to use a conservative approach. Conclusions We report a case of anomalous origin of LCx from right sinus of Valsalva causing transient myocardial ischemia in a patient that has always been asymptomatic. This anomaly has been and continues to be considered benign, nevertheless we suggest to judge the clinical significance of this kind of CA anomaly on a case-by-case integrated approach.

Techniques improving electrical cardioversion success for patients with atrial fibrillation: a systematic review and meta-analysis.

Electrical cardioversion is commonly used to restore sinus rhythm in patients with atrial fibrillation (AF), but procedural technique and clinical success vary. We sought to identify techniques associated with electrical cardioversion success for AF patients. We searched MEDLINE, EMBASE, CENTRAL, and the grey literature from inception to October 2022. We abstracted data on initial and cumulative cardioversion success. We pooled data using random-effects models. From 15 207 citations, we identified 45 randomized trials and 16 observational studies. In randomized trials, biphasic when compared with monophasic waveforms resulted in higher rates of initial [16 trials, risk ratio (RR) 1.71, 95% CI 1.29-2.28] and cumulative success (18 trials, RR 1.10, 95% CI 1.04-1.16). Fixed, high-energy (≥200 J) shocks when compared with escalating energy resulted in a higher rate of initial success (four trials, RR 1.62, 95% CI 1.33-1.98). Manual pressure when compared with no pressure resulted in higher rates of initial (two trials, RR 2.19, 95% CI 1.21-3.95) and cumulative success (two trials, RR 1.19, 95% CI 1.06-1.34). Cardioversion success did not differ significantly for other interventions, including: antero-apical/lateral vs. antero-posterior positioned pads (initial: 11 trials, RR 1.16, 95% CI 0.97-1.39; cumulative: 14 trials, RR 1.01, 95% CI 0.96-1.06); rectilinear/pulsed biphasic vs. biphasic truncated exponential waveform (initial: four trials, RR 1.11, 95% CI 0.91-1.34; cumulative: four trials, RR 0.98, 95% CI 0.89-1.08) and cathodal vs. anodal configuration (cumulative: two trials, RR 0.99, 95% CI 0.92-1.07). Biphasic waveforms, high-energy shocks, and manual pressure increase the success of electrical cardioversion for AF. Other interventions, especially pad positioning, require further study.

Algorithms for the prevention and treatment of supraventricular tachycardia in patients with implanted pacemakers: case series

Two clinical cases of prevention and relief of supraventricular tachycardia using modern algorithms in pacemakers of the latest generation in patients with bradyarrhythmia and paroxysmal atrial fibrillation (AF) are presented. In the first clinical case, the patient did not have an episode of AF for six months. In the second clinical case, the patient for 2 years did not have an episode of AF lasting more than 1 minute. Episodes sinus rhythm restoration by antitachypacing algorithms were recorded. These clinical cases demonstrate the effectiveness of modern algorithms in pacemakers of the latest generation for the AF prevention and sinus rhythm restoration.

Electric cardioversion in patients treated with oral anticoagulants: embolic material in the left atrial appendage.

Atrial fibrillation (AF) remains the most common arrhythmia. The sinus rhythm restoration procedure without adequate anticoagulant preparation may lead to a thromboembolic event in approximately 5-7% of patients. The initiation of oral anticoagulation significantly reduces this risk by inhibiting formation of embolic material in the heart cavities, especially in the left atrial appendage (LAA). However, there is a group of patients who develop embolic material in the LAA despite oral anticoagulation treatment. The best treatment method to dissolve thrombus in the LAA is not clear, due to the lack of studies with adequate power and endpoints that can determine the best management strategy. We present clinical trials comparing the efficacy and safety of oral anticoagulants in patients undergoing AF cardioversion. We evaluate the frequency of LAA thrombus formation in patients with AF on treatment with oral anticoagulants. Furthermore, we discuss the effectiveness of various treatment strategies on LAA thrombus resolution.

Response to correspondence regarding 5-year follow up of the Amaze Randomized Controlled trial of ablation treatment for arrhythmia as an adjunct to cardiac surgery.

We thank Dr Garcia-Villarreal [1] for his comment on our article in which he questions the rate of return to stable sinus rhythm in the Amaze trial [2]. We should like to point out that the Amaze trial [3] was not an evaluation of the complete Cox-maze procedure, but an evaluation of concomitant atrial fibrillation surgery as it is done in the real world. Amongst our findings, we discovered that a large variety of lesion sets were being used and that many surgeons did not complete the full biatrial lesion set in their practice. We also found that there appears to be an ablation ‘dose–response’ in achieving return to sinus rhythm, with the greatest step-up achieved when the left atrial lesion set includes the mitral isthmus lesion. We therefore agree with Dr Garcia-Villarreal that concomitant atrial fibrillation surgery should ideally be as complete as possible, and there may be an argument for concentrating such surgery in the hands of interested and experienced surgeons. Despite this, over 5 years later, we have anecdotal evidence that less complete choices of lesion sets continue to be made. We agree that the experience of surgeons devoted to atrial fibrillation should help in maximizing return to sinus rhythm and may also aid in achieving better atrial function after surgery, which is at least as important for clinical patient outcomes as electrical sinus rhythm restoration (study registration ISRCTN82731440) [4].

Rate or Rhythm Control in CRT (RHYTHMIC): Study rationale and protocol.

Atrial fibrillation (AF) has several detrimental effects on heart failure patients treated with cardiac resynchronization therapy (CRT). These include suboptimal biventricular pacing and the loss of atrioventricular (AV) synchrony. AV node ablation improves biventricular pacing and clinical outcomes in large observational studies. However, restoration of sinus rhythm with AF ablation may have additional benefits. To compare the effects of AV node ablation and AF ablation on echocardiographic and symptomatic outcomes in patients with CRT and suboptimal biventricular pacing. RHYTHMIC is a multicenter prospective randomized controlled trial. Seventy patients will be recruited and randomized to each ablation strategy in a 1:1 ratio. Key inclusion criteria include a previous CRT implant (with atrial lead) for dyssynchronous heart failure, and biventricular pacing <95% secondary to AF. Patients with permanent AF will be excluded. Patients will undergo baseline assessment including transthoracic echocardiography (TTE), device check, blood tests, electrocardiogram (ECG), 6-minute walk test, and symptom questionnaire. They will then undergo either AV node ablation or AF ablation according to their allocated group. Follow-up will occur at 1 week (TTE and ECG) and at 6 months (repeat of baseline investigations). The primary endpoint will be change in left ventricular ejection fraction on TTE. This is the first randomized controlled trial comparing AV node ablation and AF ablation in patients with CRT. We anticipate it will provide valuable insight into the management of this frequently encountered clinical scenario in a challenging patient cohort.

RADIOFREQUENCY VS. CRYOABLATION FOR PAROXYSMAL ATRIAL FIBRILLATION: A COMPREHENSIVE COMPARATIVE STUDY

Paroxysmal atrial fibrillation (PAF) presents a significant challenge in clinical management due to its recurrent nature and associated risks of stroke and other complications. Radiofrequency ablation (RFA) and cryoablation have emerged as effective strategies for restoring sinus rhythm in patients with PAF. This comprehensive comparative study aims to evaluate the efficacy, safety, and long-term outcomes of RFA versus cryoablation in the treatment of PAF. A thorough analysis of available literature, clinical trials, and observational studies was conducted to assess the procedural success rates, recurrence rates, complication rates, and quality of life outcomes associated with each ablation modality. Factors such as procedural duration, cost-effectiveness, and patient preferences were also considered. The findings of this study provide valuable insights into the optimal selection of ablation techniques for patients with PAF, guiding clinicians in personalized treatment decisions and improving overall patient care.

Surgical ablation for atrial fibrillation is efficacious in patients with giant left atria

ObjectiveThe Cox-Maze IV procedure (CMP-IV) is the most effective treatment for atrial fibrillation. Increased left atrial (LA) size has been identified as a risk factor for failure to restore sinus rhythm. This has biased many surgeons against ablation in patients with giant left atrium (GLA), defined as LA diameter >6.5 cm. In this study we aimed to define the efficacy of the CMP-IV in patients with GLA. MethodsFrom April 2004 through March 2020, 786 patients with a documented LA diameter underwent elective CMP-IV, 72 of whom had GLA. Median follow-up duration was 4 years (interquartile range, 1-7 years). Recurrence was defined as any documented atrial tachyarrhythmia (ATA) lasting 30 seconds. ATA recurrence and survival were analyzed across GLA versus non-GLA groups. ResultsMedian age at surgery was 65 (interquartile range, 56-73) years. Median LA diameter within the GLA group was 7.0 (range, 6.6-10.0) cm. There were no differences in rates of postoperative complications for the 2 groups, including rate of postoperative stroke and pacemaker placement (GLA 14%; non-GLA 12%; P = .682). A trend toward increased 30-day mortality in the GLA group did not reach statistical significance (GLA 6%; non-GLA 2%; P = .051). Freedom from ATAs at 5 years postoperatively was comparable for the 2 groups (GLA 82%; non-GLA 84%). ConclusionsThe CMP-IV had good efficacy in patients with GLA. Our results suggest that LA diameter >6.5 cm should not preclude a patient from undergoing surgical ablation for atrial fibrillation.

Mechanical function of the left atrium within 28 days after restoration of sinus rhythm in patients with paroxysmal atrial fibrillation

Objective: Atrial fibrillation is a strong independent risk factor for cardioembolic stroke, with a significant impact on morbidity, mortality and healthcare costs. The aim of our study is to investigate left atrial mechanical function in healthy subjects and patients with atrial fibrillation paroxysms less than 48 hours with low risk of thromboembolic complications at 1 and 28 days after restoration of sinus rhythm. Methods: Thirty-six healthy controls and patients with paroxysms of non-valvular atrial fibrillation less than 48 hours (n=25) with low-risk CHA2DS2VASc score were included in the study. The mechanical function of the left atrium (LA) was investigated by the 2D speckle tracking program. Transthoracic echocardiography was performed on the 1st and 28th days after restoration of sinus rhythm by pharmacological cardioversion. Results: Despite the absence of differences in left ventricular systolic function and LA size between the groups, there was a significant decrease in LA deformation and strain rate on day 1 immediately after sinus rhythm recovery in the patients. In the pump phase, the decrease was about 3%, reservoir phase – 10%, and conduit phase – 7% compared to the control group. The strain rate also decreased in the patient group: -1.5 s-1 versus control: -2.14 s-1 (p&amp;lt;0.0001). On the 28th day after restoration of sinus rhythm, there were significant changes in reservoir and conduit functions in patients group in comparison with control group. Global longitudinal LA strain (reservoir phase) decreased to 7%, conduit phase decreased to 11% compared with the control group. In patients group we can see the dynamics during 28 days: pump phase and strain rate were significantly improved, however reservoir and conduit did not significantly change and were lower than in healthy. Conclusion: Mechanical function of the LA in patients with non-valvular atrial fibrillation and low risk of thromboembolic complications, studied with speckle tracking on the first day was significantly impaired compared with the control group (reservoir phase and strain rate). By day 28, mechanical function improved compared to day 1, but reservoir phase remained significantly lower than normal.

The many NOs to the use of Class IC antiarrhythmics: weren't the guidelines too strict?

Class IC antiarrhythmic drugs (AADs) currently represent a cornerstone in the therapy of atrial fibrillation, both for the restoration of sinus rhythm and for the prophylaxis of long-term relapses. They also play an important role in the treatment of idiopathic ventricular arrhythmias. Following the results of the Cardiac Arrhythmia Suppression Trial study, flecainide and by extension the other Class IC AADs were contraindicated in patients with ischaemic and structural heart disease, due to their pro-arrhythmic effect and the consequent increase in mortality observed in the study. Recent studies carried out on patients with chronic coronary heart disease without previous heart attacks and/or residual ischaemia have shown a good safety profile for this class of drugs. In addition, other studies have shown excellent efficacy in the absence of pro-arrhythmic effects of Class IC AADs in patients with structural heart disease such as arrhythmogenic right ventricular cardiomyopathy (ARVC) and tachy-cardiomyopathy. The purpose of this review is to evaluate the appropriate use of Class IC AADs in the different patient subgroups, in the light of the evidence and new diagnostic and therapeutic tools available.

Predictors of sinus rhythm restoration in patients with long-term episodes of persistent atrial fibrillation

The aim – to compare clinical, laboratory and instrumental characteristics of patients with persistent atrial fibrillation (AF) and duration of AF episode ≥ 90 days, undergoing direct current (DC) cardioversion, in groups with or without further sinus rhythm (SR) restoration, for the purpose of determining the predictors of SR restoration.Materials and methods. The cohort single-center study analyzed clinical, laboratory and instrumental data from 115 persistent AF patients with duration of its episode ≥ 90 days, who underwent an elective direct current cardioversion. Patients were subdivided into the groups depending on SR restoration effectiveness: 59 (51.3 %) and 56 (48.7 %) patients with restored and non-restored SR, respectively.Results and discussion. The group of patients with non-effective DC cardioversion was characterized more severe heart failure (HF) and more frequent percutaneous coronary intervention (PCI) cases, as opposed to the group with restored SR. The studied groups differed significantly by the certain echo parameters, characterizing the structure and function of left heart chambers. The transthoracic echocardiography (TTE) revealed a higher left ventricular (LV) dilatation and more frequent pulmonary hypertension (PH) cases in non-restored SR group. According to transesophageal echocardiography (TEE) data, both groups demonstrated the deterioration of left atrial (LA) function, namely the decrease of LA appendage flow velocity ≤ 40 cm/s in more than 60 % of patients. Additionally, the LA spontaneous echo contrast (SEC) was visualized in vast majority of non-restored SR patients (94.6 %). At the same time, only 2 (3.6 %) patients with non-effective DC cardioversion were free from SEC, as compared to 44 (74.6 %) restored SR patients (р &lt; 0.001). The multivariable logistic regression analysis revealed SEC as an independent predictor of SR restoration.Conclusions. Persistent AF patients with duration of its episode ≤ 90 days and non-effective elective DC cardioversion demonstrated higher stage of HF, more frequent demand for PCI, the higher LV dilatation, and presence of PH (TTE) and LA SEC (TEE). Among other associated factors, the freedom from LA SEC appeared to be the only independent predictor of SR restoration in such patients.

Abstract 12770: Immune Checkpoint Inhibitor Induced Myocarditis: An Interesting Case of Reversible Complete Heart Block

BACKGROUND: Immune checkpoint inhibitors (ICI) have changed the treatment scope for malignancies. The mechanism of ICIs is targeting of immune checkpoints that can suppress a response to a stimulus which can effect any organ. Adverse effects are usually mild but myocarditis, although rare, is becoming more recognized as a life threatening entity. The increase in mortality seen with ICI-induced myocarditis is more frequent with combination therapy. Most cases of ICI-induced myocarditis are limited to direct myocardial injury but there is a lack of evidence regarding conduction disease. CASE DESCRIPTION: We present a 74-year-old man with known metastatic malignancy recently started on ICI with ipilimumab and nivolumab who presented with complaints of abdominal pain, SOB and chest pain. His ED workup was consistent with colitis and acute PE without RV strain. Troponins and BNP were elevated and his ECG showed 3rd degree AV block. A coronary angiogram was negative for obstructive CAD and a temporary trans-venous pacemaker was placed. Cardiac MR showed LGE with active inflammation of the mid-myocardium. The patient had complex presentation as a side effect of ICI leading to myocarditis, 3rd degree AV block, colitis and PE. He was started on high dose methylprednisolone 1gm daily. Within 24 hours there was improvement evidenced by intermittent return of intrinsic conduction. At 48 hours there was marked improvement with restoration of sinus rhythm without evidence of AV block and/or use of the temporary pacemaker. Discussion: Early recognition of disease processes is difficult when there is minimal data to support a cause and effect. Increasing clinical awareness regarding adverse effects of ICI is paramount in decreasing the risk for unnecessary therapies, in our case, placement of a permanent pacemaker. Although there have been case reports of ICI-induced myocarditis, there has not been expert consensus regarding management of conduction pathway abnormalities.

Abstract 13131: Three-Dimensional Echocardiography Left Atrial Appendage Dimensions is a Reflect of Cardiac Rhythm at Mid-Term Follow-Up in Atrial Fibrillation Patients

Introduction: Few studies have described the characteristics of the left atrial appendage (LAA) using three dimensional (3D) transesophageal echocardiography (TEE) in atrial fibrillation (AF). Hypothesis: We hypothesized that 3D characteristics of the LAA could further characterize patients in AF. Methods: We prospectively evaluated 156 patients hospitalized for AF with two-dimensional (2D) transthoracic and 3D TEE of the LAA within 24 hours of admission. 3D parameters were off-line analysed with Tomtec software (4D Cardio-View, Generic Volume, Philips) (Figure 1A). Patients were divided into two groups according to the cardiac rhythm at 2 years of follow up: restoration of sinus rhythm (SR group, 107 patients) or persistence of atrial fibrillation (AF group, 49 patients). Results: The mean age of the population was 66±11 years and 95 (61%) patients were male. At admission using 2D transthoracic echocardiography, AF group had in comparison with SR group higher left atrial end-systolic volume indexed (respectively 48.0 (38.7-57.0) versus 41.8 (35.0-51.5) ml/m 2 , p=0.0096), higher E velocity (respectively 0.90 (0.78-1.00) versus 0.76 (0.62-0.91) m/s, p= 0.0001) and higher pulmonary arterial pressure (respectively 31 (25-38) versus 28 (23-33) mmHg, p=0.0142). There were no significant differences in left ventricle ejection fraction and right atrial end-systolic volume indexed. At admission using 2D TEE, AF group had in comparison with SR group lower emptying flow velocity (29 (20-38) versus 38 (26-53) cm/s, p=0.002) and filling flow velocity (29 (20-39) versus 40 (29-56) cm/s, p=0.001) of the LAA. In 3D TEE, AF group had higher 3D end-systolic and end-diastolic LAA volumes (non-indexed and indexed) and no significant differences in LAA ostium in comparison with SR group (Figure 1B). Conclusions: 3D evaluation of the LAA reflects a degree of cardiac cavities remodeling in AF and seems to be associated with the evolution of cardiac rhythm at two-years follow-up.

Abstract 15528: Indeterminate Cardiomyopathy in a Patient With Birt Hogg Dubé Syndrome and a Clinical Diagnosis of Scleroderma and Prior Atrial Tachy Arrhythmias: A Diagnostic and Therapeutic Dilemma

Birt Hogg Dubé (BHD) syndrome, tachycardia induced cardiomyopathy and scleroderma are three well defined diagnoses. A link between them has not been reported. We present a diagnostic and treatment challenge, of a patient with BHD, clinical scleroderma and prior tachycardia induced cardiomyopathy with persistent left ventricular dysfunction despite restoration of sinus rhythm. Mr. X medical history includes recurrent bilateral pneumothoraces and bullectomy, with a cystic lung disease. He was diagnosed with BHD syndrome in 2018. He was diagnosed clinically with scleroderma with myositis based on symptoms and clinical signs with paucity of inflammation on muscle biopsy and negative biomarkers. There has been a limited response to immunosuppressants. In 2020 he presented with symptomatic paroxysmal atrial fibrillation. CMRI showed biventricular dilatation with increased volumes with LVEF of 40%, ​RVEF of 25% in sinus bradycardia. LGE showed subendocardial signal in ​​the basal and mid segment of the lateral and posterolateral walls with small foci of myocardial ​​​signal at the basal and mid inferior RV-LV hinge points. A bespoke CRT-D (secondary to cavity size) was inserted following documented broad complex tachycardia, given the history of reduced ejection fraction despite medical therapy. Right and left heart catheterisations were normal. Endomyocardial biopsy showed no pathological features and no fibrosis or evidence of infiltrative disease. Genotype results are pending. BHD is a genetic disorder, affecting folliculin protein, associated with cystic lesions of the lung, kidney, and skin with an increased risk of renal cell carcinoma (1). There is no known link of BHD syndrome with cardiomyopathy. Studies have demonstrated folliculin has a role in cardiomyocyte generation (2). Given the cardiac biopsy result, not in keeping with scleroderma or tachycardia induced cardiomyopathy, he may have an independent cardiomyopathy, or a first case of cardiomyopathy secondary to BHD. Our challenge continues to be optimising available therapies ensuring the best quality of life, whilst balancing the potential need for cardiac transplant with lifelong immunosuppressant therapy in a condition which has a seven-fold increased risk of renal cancer.

Abstract 15766: A Perfect [vt] Storm - How All the Wrong Factors Converged During a Dofetilide Load

Background: Dofetilide is a class III antiarrhythmic often used for the treatment of atrial fibrillation. Given its QTc prolonging properties, it is invariably initiated in an inpatient setting. While admissions for this drug are often unexciting, pharmacologic cardioversion in general and dofetilide in particular carry unique hazards. Objective: To review a case where several risk factors converged during a dofetilide load to produce a life threatening event. Case: A 75 year old male in persistent atrial fibrillation was admitted for dofetilide and started on 500 mcg PO Q12 (based on QTc and GFR). He did not experience any QTc prolongation after his first two doses, and converted to sinus rhythm on his second day of hospitalization. With this, he had an abrupt decrease in heart rate from 110 to 60 bpm. Within minutes, he suddenly developed flash pulmonary edema and required treatment for acute heart failure with IV diuresis. Fortunately, he improved with therapy in time to receive his third dose, after which QTc remained at 450. However, he had non sustained polymorphic ventricular ectopy overnight. His full AM dose was given before the monitor was reviewed (given his normal QTc), and within 2 hrs of this fourth dose, QTc prolonged markedly. He developed ventricular bigeminy with long-coupled PVCs. Subsequently, he developed sustained torsades requiring chest compressions and defibrillation. The patient recovered well, and dofetilide was discontinued. Conclusion: Acute heart failure after restoration of sinus rhythm is an uncommon but known complication of cardioversion, both electrical and pharmacologic. Furthermore, hemodynamic derangement is known to decrease arrhythmia threshold, which, along with his abrupt drop in heart rate and recent diuresis, likely contributed to the development of torsades. Furthermore, while his QTc appeared numerically acceptable before the fourth dose was given, later review revealed an abnormal T wave morphology with prolonged T peak to end time, which might have prompted a dose change if recognized. In short, monitoring dofetilide patients involves more than just GFR and QTc - other observable factors can portend poor outcome.

Abstract 12553: Adverse Cardiovascular Outcomes in Heart Failure (HF) With Preserved Systolic Function Associated With Atrial Fibrillation Are Due to Loss of Rhythm Control Impacting HF Status : A Propensity Score Matched Analysis of the TOPCAT Americas Study

Background: Atrial fibrillation (AF) is associated with excess mortality and cardiovascular (CV) hospitalizations in HF patients (pts) with preserved systolic function (pEF), Whether this is due to advanced co-morbidities or loss of atrioventricular (AV) synchrony &amp; rate control in AF is unclear. Hypothesis: To analyze the independent impact of AF on clinical outcomes of HFpEF pts in the TOPCAT AMERICAS study using propensity score matched (PSM) cohorts to account for confounding by other comorbidities. Methods: Study cohorts were matched for 20 clinical, demographic &amp; ECG variables. 3 matched cohorts based on baseline rhythm status at study entry were compared viz. subjects in sinus rhythm (SR), subjects in AF on baseline ECG &amp; subjects with Any AF event by history or ECG. We analyzed CV mortality, adjudicated modes of death &amp; morbidity during a mean follow up period of 2.9 yrs. Results: 418 subjects in SR (SR cohort) were PSM with 418 subjects in AF on baseline ECG (AF on ECG cohort) &amp; 418 pts with any AF event by history or ECG (Any AF cohort) at study entry. Any AF increased risk of CV death(D), pump failure death (PFD), CV and HF hospitalization(H) and HF progression. AF on ECG increased risk of CVD, CVH, HFH and PFD (Tables). Neither AF cohort increased risk of sudden death (SD) {Figure}. Conclusion: 1. AF is an independent risk factor for worsening CV outcomes in HFpEF. 2. This increased risk is due to a selective increase in HF worsening, HFH and PFD rather than SD. 3. Loss of AV synchrony &amp; rate control in AF can independently impact HF progression in HFpEF with consequent HFH and PFD. Restoration of SR may offer benefits for CV outcomes in HFpEF &amp; warrants evaluation.

Abstract 9267: Modified Protocol of Niferidil Administration for Rhythm Restoration in Patients With Paroxysm of Atrial Fibrillation

Introduction: Niferidil is a new Russian class III antiarrhythmic drug, which in clinical trials has shown a high efficiency of restoration of sinus rhythm (SR) in persistent AF (87%), not inferior to electrical cardioversion. Currently, a three-stage scheme of drug administration is used (10 μg / kg - 10 μg / kg - 10 μg / kg). In a number of patients, SR is restored before the end of the first dose of the drug, which indicates the effectiveness of an even lower dose (5 μg / kg) of the drug, which has not been studied in clinical trials. Objective: To evaluate the effectiveness and safety of the modified protocol of niferidil administration in patients with paroxysmal AF. Methods: Included 87 patients with paroxysmal, 42 of them were men, mean age 63 [57;70]. After exclusion of contraindications, all patients received niferidil according to the following scheme. The initial dose of niferidil was 5 μg/kg of body weight, if AF did not terminate after 15 minutes (min.), niferidil was additionally administered at a dose of 5 μg/kg (total dose of 10 μg/kg). If SR was not restored patients received subsequent injections of niferidil 10 μg/kg, each after 15 min. (maximal total dose of 30 μg/kg). Injections were discontinued in case of SR restoration, QTc&gt;500ms or proarrhythmia. All patients underwent continuous ECG monitoring within 24 hours to assess effectiveness and safety of niferidil. Results: SR was restored in 81 out of 87 patients (cumulative effectiveness of niferidil in doses up to 30 μg / kg was 93,1 %. 49,4 % of them restored SR after administration of 5 μg/kg dose, 66 (77 %) - after 10 μg/kg dose, 77 (88,5 %) - after 20 μg/kg dose, 81 (93,1 %) - after 30 μg/kg dose. In none of the cases was there any development of life-threatening ventricular arrhythmias. Prolongation of the QTc&gt;500 ms was recorded in 14 patients (16%). Bradyarrhythmias after SR recovery were reported in 6 patients (6,8 %). In all cases sinus bradycardia was asymptomatic. Conclusions: The modified protocol of cardioversion allows SR to be restored in a significant number of AF patient’s lower doses of niferidil. The drug is highly effective in the treatment of paroxysmal AF, while in almost half of the cases, SR is restored after the administration after drug dose - 5 μg / kg. None of the patients developed Torsades de pointes.

P-wave duration and interatrial conduction abnormalities in paroxysmal and persistent typical atrial flutter.

Functional and structural changes, the enlargement of the right atrium is the background for the development of typical atrial flutter (AFL). These changes in ECG are manifested in the morphology of the initial part of the P-wave. The aim of the study was to assess the duration and morphology of the P-wave in patients with paroxysmal and persistent AFL. The study population consisted of 131 patients with AFL, 38 women and 93 men aged 66 years (60-72), divided in 62 patients with paroxysmal and 69 with persistent AFL. P-wave duration was measured with an electrophysiological system in all leads at a paper speed of 200 mm/s. The groups did differ in terms of gender (38/24 vs. 55/14, (M/F), p=0.033). Patients with persistent AF had a longer P-wave duration - 175±26.3 ms vs. 159±22.6 ms, p=0.01, and higher creatinine concentration - 1.2±0.60 mg/dl vs. 1.08±0.68 mg/dl, p=0.007. The presence and severity of interatrial conduction block (I-none, II-partial, III-total) was related to age of the patients (60.3±12.1 vs. 64.7±-8.3 vs. 68.9±9.5 years, respectively). Patients with persistent AFL show a longer P-wave compared to paroxysmal AFL, regardless of comorbidities and antiarrhythmic drugs. The arrhythmia-related longer P-wave duration should encourage the clinicians to restore sinus rhythm earlier in order to more effectively maintain it over the long term.