A new perspective on atrial tachycardia-induced cardiomyopathy: The misdiagnosis of epigastric pain in an 11-year-old girl.

Epigastric pain can be a common clinical manifestation of many diseases, but severe subxiphoid pain caused by tachycardia-induced cardiomyopathy is extremely rare in children. Therefore, the clinical manifestations of the disease are diverse, and improving early detection and treatment of the disease can avoid possible risks. In the case, we report an 11-year-old girl who was initially diagnosed with acute gastritis in a local hospital, but was later diagnosed with atrial tachycardia-induced cardiomyopathy in our hospital after active diagnosis and effective treatment, suggesting early detection and intervention is possible to prevent subsequent serious events.

Usefulness of tissue tracking to differentiate tachycardia-induced cardiomyopathy from dilated cardiomyopathy in patients admitted for heart failure.

INTRODUCTION: Differentiation of tachycardia-induced cardiomyopathy (TIC) from dilated cardiomyopathy (DCM) in patients admitted for heart failure (HF) with left ventricular dysfunction and supraventricular tachyarrhythmia (SVT) remains challenging. The role of tissue tracking (TT) in this setting remains unknown. METHODS: Forty-three consecutive patients admitted for HF due to SVT with left ventricular ejection fraction (LVEF) < 50% undergoing CMR were retrospectively included. Those eventually evolving to LVEF > 50% at follow-up were classified as TIC and those maintaining a LVEF < 50% were classified as DCM. Clinical, echocardiography, and CMR findings, including TT, were analyzed to predict LVEF recovery. RESULTS: Twenty-five (58%) patients were classified as TIC. Late gadolinium enhancement (LGE) was more frequent in DCM group (61% vs 16%, p = 0.004). Left ventricle (LV) peak systolic radial velocity and peak diastolic radial strain rate were lower in DCM group (7.24 ± 4.44 mm/s vs 10.8 ± 4.5 mm/s; p = 0.015 and -0.12 ± 0.33 1/s vs -0.48 ± 0.51 1/s; p = 0.016, respectively). Right ventricle (RV) peak circumferential displacement was lower in patients with TIC (0.2 ± 1.3 vs 1.3 ± 0.9°; p = 0.009). In the multivariate analysis, diabetes (p = 0.046), presence of LGE (p = 0.028), LV peak systolic radial velocity < 7.5 mm/s (p = 0.034), and RV peak circumferential displacement > 0.5° (p = 0.028) were independent predictors of lack of LVEF recovery. CONCLUSION: In the setting of acute HF with LV dysfunction related to SVT, diabetes, LGE, LV peak systolic velocity, and RV peak circumferential displacement are independent predictors of lack of LVEF recovery and, therefore, represent clinically useful parameters to differentiate TIC from DCM.

Left Atrial Low-Voltage Zone Assessment and Voltage-Guided Ablation Outcome in Patients With Atrial Fibrillation-Induced Tachycardiomyopathy.

BACKGROUND: Persistent atrial fibrillation (AF) patients with tachycardia-induced cardiomyopathy (TIC) undergoing catheter ablation have similar or even better outcomes than patients without TIC. Data regarding atrial substrate remodeling are scarce in cases of TIC. We assessed regional distribution of left atrial (LA) bipolar voltage, the extent of low-voltage zones (LVZs), and outcomes of voltage-guided ablation in AF patients with and without TIC. METHODS AND RESULTS: In all, 139 patients with persistent AF presenting for a first voltage-guided catheter ablation were enrolled, 61 with TIC and 78 with structurally normal hearts. LA voltage maps were obtained using a 3-dimensional electroanatomical mapping system in sinus rhythm. LVZ was defined as <0.5 mV. Compared with non-TIC patients, TIC patients had a lower indexed LA volume (median [interquartile range] 58.6 [50.6-68.7] vs. 63.4 [60.1-76.1] mL/m2; P<0.01) and higher LA voltage (2.3 [1.5-2.8] vs. 1.7 [1-2.6] mV; P=0.02). LVZs were less frequently found in patients with than without TIC (8 [13.1%] vs. 30 [39%]; P<0.01). There was no significant difference in atrial tachyarrhythmia (AT)-free survival rate over a 36-month follow-up between the 2 groups (log-rank test, P=0.176). No predictor of AT recurrence was identified. CONCLUSIONS: TIC patients exhibit less LA substrate remodeling with a smaller LA volume, higher bipolar voltage, and fewer LVZs than non-TIC patients. They have a similar favorable outcome after a single procedure.

Decreased plasma cell-free mitochondrial DNA may be a new biomarker of tachycardia-induced cardiomyopathy in patients with atrial fibrillation.

OBJECTIVES: To determine cell-free mitochondrial DNA (mt-cfDNA) levels in tachycardia-induced cardiomyopathy (TIC) and non-TIC among atrial fibrillation (AF) cases. BACKGROUNDS: TIC is a reversible cardiomyopathy resulting from tachyarrhythmias, such as AF. The exact cause of TIC is not fully understood, but mitochondrial dysfunction has been reported in a variety of cardiomyopathies and may be involved in TIC as well. AF is recognized to be associated with systemic inflammation, and studies have shown that in patients with AF have elevated levels of mt-cfDNA increased, and this increase is linked to systemic inflammation. METHODS: We enrolled 67 patients with TIC (TIC group) and 671 patients without TIC (non-TIC group), who underwent catheter ablation for AF at our hospital between November 2009 and September 2016 and did not meet the exclusion criteria. We performed quantitative PCR analysis of plasma mt-cfDNA and nuclear-cfDNA and compared clinical factors and these measurements between the two groups. RESULTS: Levels of mt-cfDNA were significantly lower in the TIC group than in the non-TIC group (1110.01 vs. 1918.71 copies/µg plasma, P = 0.027), while levels of nuclear-cfDNA were comparable between these two groups. In particular, mt-cfDNA (P = 0.0003, odds ratio [OR] 2.54), non-paroxysmal AF (P < 0.0001, OR 3.07), and diabetes mellitus (P = 0.006, OR 2.36) were identified as independent factors associated with TIC. CONCLUSION: There are lower mt-cfDNA in TIC, and decreased plasma levels of circulating mt-cfDNA may be a new biomarker and involve in related mechanisms for AF associated TIC. CONDENSED ABSTRACT: Tachycardia-induced cardiomyopathy (TIC) is a reversible cardiomyopathy caused by tachyarrhythmias, such as atrial fibrillation (AF) tachycardia. The pathogenesis of TIC remains incompletely understood, and there is currently no method to predict its development in patients. In this study, we show that cell-free mitochondrial DNA (mt-cfDNA) levels were significantly lower in the TIC group than in the non-TIC group. Persistent AF, coexisting diabetes mellitus, and decreased mt-cfDNA levels were independently associated with TIC. Decreased mt-cfDNA levels may serve as a novel biomarker for predicting TIC in patients with AF.

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.

Risk factors for tachycardia-induced cardiomyopathy due to atrial fibrillation.

BACKGROUND: Tachycardia-induced cardiomyopathy (TIC) is a reversible cardiomyopathy with ventricular dysfunction caused by tachyarrhythmias. Notably, atrial fibrillation (AF) is the most common causal arrhythmia leading to TIC. However, the risk factors for the development of TIC due to AF remain unclear. This study aimed to identify the associated factors of TIC due to AF. METHODS: Persistent AF patients with heart rate (HR) ≥100 beats per minute who underwent initial catheter ablation were enrolled in this study. TIC was diagnosed as left ventricular ejection fraction (LVEF) < 50% during AF rhythm, which was recovered after the restoration of sinus rhythm. Non-TIC was defined as LVEF ≥ 50% despite AF rhythm. The patient backgrounds were compared between the TIC group and the non-TIC group to reveal the contributing factors of TIC. RESULTS: The TIC group comprised 57 patients, while the non-TIC group consisted of 101 patients. The TIC group was younger than the non-TIC group (median 64 vs. 70, p = 0.006). Male sex was more frequent in the TIC group than the non-TIC group (82.5% vs. 58.4%, p = 0.003). HR was higher in the TIC group than in the non-TIC group (median 130 bpm vs. 111 bpm, p < 0.001). The number of smokers was significantly higher in the TIC group than in the non-TIC group (p < 0.001). Multivariable analysis demonstrated that higher HR (odds ratio [OR]: 1.74; 95% confidence interval [CI]: 1.37-2.21; p < 0.001) and current smokers (OR: 5.27; 95% CI: 1.60-17.4; p = 0.006) were the independent factors leading to TIC. CONCLUSION: Higher HR and current smokers were independent risk factors for the development of TIC due to AF.

Tachycardia-Induced Cardiomyopathy in an Infant with Atrial Flutter and Prolonged Recovery of Cardiac Function.

Background: Tachycardia-induced cardiomyopathy (TIC) is caused by prolonged tachycardia, leading to left ventricular dilatation and systolic dysfunction with heart failure. Although TIC is more common in adults, it is rare in early infancy. Methods: Clinical testing was performed as part of medical evaluation and management. Next-generation sequencing (NGS) was conducted for a patient with TIC. A literature review on TIC was also conducted. Results: The case involved a 5-month-old infant referred to the hospital due to symptoms of heart failure lasting at least two months. The infant's heart rate was 200 beats per minute, the left ventricular ejection fraction fell below 14%, and electrocardiograms showed atrial flutter, suggesting TIC. After cardioversion, there was no recurrence of atrial flutter, and cardiac function improved 98 days after tachycardia arrest. The NGS did not identify any pathogenic variants. The literature review identified eight early infantile cases of TIC. However, no previous reports described a case with such a prolonged duration of TIC as ours. Conclusions: This is the first report of a case of prolonged TIC in a child with the documented time to recover normal cardiac function. The improvement of cardiac function depends on the duration of TIC. Early recognition and intervention in TIC are essential to improve outcomes for infantile patients, as timely treatment offers the potential for recovery.

Predictors of systolic function recovery after atrial fibrillation ablation in heart failure patients.

INTRODUCTION AND OBJECTIVES: Atrial fibrillation (AF) and heart failure (HF) often coexist. AF catheter ablation improves left ventricular ejection fraction (LVEF), but its impact varies between patients. We aimed to identify predictors of LVEF improvement in HF patients with impaired LVEF undergoing AF ablation. METHODS: We conducted a retrospective single-center study in HF patients with LVEF <50% undergoing AF catheter ablation between May 2016 and May 2022. The primary endpoint was the LVEF recovery rate ('responders'). Secondary endpoints were one-year safety and effectiveness. We also aimed to validate a prediction model for LVEF recovery. RESULTS: The study included 100 patients (79% male, median age 60 years, 70% with probable tachycardia-induced cardiomyopathy [TIC], mean LVEF 37%, 29% with paroxysmal AF). After a median follow-up of 12 months after catheter ablation, LVEF improved significantly (36±10% vs. 53±10%, p<0.001), with an 82% responder rate. A suspected diagnosis of TIC (OR 4.916 [95% CI 1.166-20.732], p=0.030), shorter QRS duration (OR 0.969 [95% CI 0.945-0.994], p=0.015), and smaller left ventricle (OR 0.893 [95% CI 0.799-0.999], p=0.049) were independently associated with LVEF improvement. Freedom from any documented atrial arrhythmia was 86% (64% under antiarrhythmic drugs), and the rate of adverse events was 2%. The prediction model had a good discriminative performance (AUC 0.814 [95% CI 0.681-0.947]). CONCLUSION: In AF patients with HF and impaired LVEF, suspected TIC, shorter QRS duration, and smaller LV diameter were associated with LVEF recovery following AF catheter ablation.

Combination of electrophysiological mapping, radiofrequency catheter ablation, and atrial appendectomy in a 5-year-old girl with tachycardia-induced cardiomyopathy: a case report.

BACKGROUND: Atrial tachycardia (AT) originating from the left atrial appendage (LAA) is uncommon and the most difficult arrhythmia to eliminate. Therefore, we present the case of a 5-year-old girl with tachycardia-induced cardiomyopathy (TIC) caused by AT originating from the LAA and successfully treated with RFCA associated to left atrial appendectomy. With resolution of AT, we observed a progressive improvement of LV function. The effectiveness and safety of this combination therapy were evaluated over a one-month follow-up period. CASE PRESENTATION: A 5 -year-old female was evaluated for three days of incessant cough and a syncopal episode. Surface echocardiography and 24-hour monitoring showed that the infant had persistent atrial tachycardia. Echocardiography revealed an enlarged tele diastolic diameter (46.1 mm) and malfunctioning (EF 28.53%) left ventricle. The location of the lesion at the apex of the LAA was further confirmed by electrophysiological study and RFCA. After RFCA, the infant's ECG monitor showed that sinus rhythm was maintained for up to 22 h. Subsequently, atrial tachycardia recurred and sinus rhythm disappeared. Finally, atrial appendectomy was performed and sinus rhythm returned to normal. CONCLUSIONS: The heart function of the infant improved and sinus rhythm was maintained, further demonstrating the safety and effectiveness of combined treatment with RFCA and atrial appendectomy after electrophysiological localization of AT from LAA to TIC.

Permanent junctional reciprocating tachycardia due to an atypical retrograde slow conducting decremental left posterolateral accessory pathway and tachycardia-induced cardiomyopathy in a pregnant adolescent.

Permanent junctional reciprocating tachycardia (PJRT) is a rare form of supraventricular tachycardia (SVT) due to a retrograde slow conducting decremental accessory pathway (AP) which is often incessant and can lead to tachycardia-induced cardiomyopathy (TIC). We report the challenging clinical course of a pregnant adolescent with PJRT due to an atypical retrograde slow conducting decremental left posterolateral AP. Pregnancy is known to exacerbate supraventricular arrhythmias and can lead to adverse maternal and fetal outcomes. To the best of our knowledge, there are no prior reports on the clinical course of rare incessant and difficult-to-treat arrhythmias such as PJRT in a pregnant adolescent patient.

Predicting factors for omitting beta-blockers in patients with tachycardia-induced cardiomyopathy after successful catheter ablation for atrial fibrillation.

Tachycardia induces a reduction in the left ventricular ejection fraction (LVEF), which is defined as tachycardia-induced cardiomyopathy (TIC). Conversion to and maintenance of sinus rhythm by catheter ablation can improve LVEF in patients with TIC due to atrial fibrillation (AF). Beta-blockers are mandatory for the treatment of heart failure with reduced LVEF(HFrEF), but the necessity of beta-blockers in TIC patients even after catheter ablation remains unclear. We examined the effect of beta-blockers on cardiac function in TIC patients after catheter ablation. We retrospectively analyzed 124 patients with a history of heart failure and an LVEF of ≤ 50% who underwent catheter ablation for AF. TIC was defined as a ≥ 10% improvement in the baseline LVEF and an improvement to an LVEF of ≥ 50% at 6 months after ablation. Patients with other cardiomyopathy diagnosed before the ablation were excluded. LVEF was significantly increased with the reductions of the left ventricular and left atrial volumes at the 6-month follow-up in all 80 patients with TIC. No beta-blockers were prescribed during the post-ablation follow-up in 21 patients with TIC. The absolute values of and changes in the echocardiographic parameters between before and after ablation were not significantly different between patients with and without beta-blockers after the ablation. A simple score using the history of hospitalization for heart failure and use of beta-blockers or diuretics prior to ablation was useful in identifying TIC patients who did not need prescription of beta-blockers after catheter ablation. LVEF similarly improved in both patients with and without prescription of beta-blockers after the ablation. Beta-blockers may not need to be prescribed after successful catheter ablation for AF in LVEF of ≤ 50% patients without other cause of cardiomyopathy diagnosed before the ablation, a history of hospitalization for heart failure and prescription of beta-blockers and diuretics before the ablation.

Severity of Left Ventricular Dysfunction in Patients With Tachycardia-Induced Cardiomyopathy: Impacts on Remodeling After Atrial Flutter Ablation.

Tachycardia-induced cardiomyopathy is defined as a reversible left ventricular (LV) systolic dysfunction (SeD) resulting from a sustained fast heart rate. LV remodeling in patients with severe LV dysfunction at diagnosis remains poorly understood. In this retrospective cohort study, we described LV remodeling in 50 patients who underwent atrial flutter ablation. These patients were divided into severe LV SeD (LV ejection fraction [EF] ≤30%) and LV nonsevere SeD (LVEF 31% to 50%) at baseline. All continuous variables are expressed as median and interquartile range. LVEF was 18% (13 to 25) and 38% (34 to 41) in the SeD (n = 29) and LV nonsevere SeD (n = 21) groups, respectively. At baseline, patients with SeD had higher LV end-diastolic diameter (56 [54 to 59] vs 49 mm [47 to 52], p <0.01), LV end-systolic diameter (48 [43 to 51] vs 36 mm [34 to 41], p <0.01), LV end-diastolic volume (71 [64 to 85] vs 56 ml/m2 [46 to 68], p <0.01), LV end-systolic volume (56 [53 to 70] vs 36 ml/m2 [27 to 42], p <0.01), and lower tricuspid annular plane systolic excursion (12 [10 to 13] vs 16 mm [13 to 19], p <0.01). At last follow-up, LVEF was not statistically significantly different between groups. However, LV end-systolic diameter (36 [34 to 39] vs 32 mm [32 to 34], p = 0.01) and LV end-systolic volume (29 [26 to 35] vs 25 ml/m2 [20 to 29], p = 0.02) remained larger in the SeD group. Seven patients (14%), all from the SeD group, had a LVEF ≤35% 2 months after rhythm control, and reverse remodeling was observed up to 9 months. In conclusion, more than half of patients with tachycardia-induced cardiomyopathy and atrial flutter had LVEF ≤30% at baseline. LVEF recovery and LV remodeling were observed beyond 2 months, highlighting the importance of rhythm control and early guideline-directed medical therapy in these patients.

Cardiac Magnetic Resonance in Patients with Suspected Tachycardia-Induced Cardiomyopathy: The Impact of Late Gadolinium Enhancement and Epicardial Fat Tissue.

Tachycardia-induced cardiomyopathy (TIC) is a reversible subtype of dilated cardiomyopathy (DCM) resulting from sustained supraventricular or ventricular tachycardia and diagnosed by the normalization of left ventricular ejection fraction (LVEF) after stable sinus rhythm restoration. The aim of this study was to determine the contribution of cardiac magnetic resonance (CMR) to the differential diagnosis of TIC and DCM with persistent atrial arrythmias in patients hospitalized for the first time with heart failure (HF) with reduced LVEF of nonischemic origin. A total of 29 patients (age: 58.2 ± 16.9 years; males: 65.5%; average EF: 37.0 ± 9.5%) with persistent atrial tachyarrhythmia and first decompensation of HF without known coronary artery diseases were included in this study. The patients successfully underwent cardioversion and were observed for 30 days. The study population was divided into groups of responders (TIC patients; N = 16), which implies achieving FF > 50% or its increase > 10% in 30 days of TIC, and non-responders (N = 13). The increase in left ventricle (LV) volumes measured using CMR was significantly higher in the non-responder group when compared with the responders (114.8 mL ± 25.1 vs. 68.1 mL ± 10.5, respectively, p < 0.05). Non-responders also demonstrated decreased interventricular septum thickness (9.1 ± 0.8 vs.11.5 ± 1.3, respectively, p < 0.05). Late gadolinium enhancement (LGE) was observed in 12 patients (41.4%). The prevalence of LGE was increased in the non-responder group (25.0% vs. 65.1%, respectively, p = 0.046). Notably, a septal mid-wall LGE pattern was found exclusively in the non-responders. Epicardial adipose tissue thickness was decreased in the non-responder group versus the TIC patients. Conclusion: Patients with TIC were found to have smaller atrial and ventricular dimensions in comparison to patients with DCM. In addition, LGE was more common in DCM patients.

Coumel tachycardia in children.

BACKGROUND: Coumel tachycardia is an infrequent form of supraventricular tachycardia (SVT) that usually occurs in infants and children. It is a tachycardia mediated by an accessory pathway with retrograde slow conduction that explains the classic ECG pattern with long RP' interval and negative P waves in leads II, III, and aVF. In this study, we describe the clinical course and management of Coumel tachycardia in children. CASE REPORT: We conducted a retrospective review of five consecutive pediatric patients, mean age 11 ± 3 years (range 6 to 14). The first episode of SVT was at a mean age of 10.4 ± 4.8 years (range 2 to 14) with a mean evolution of 7.4 ± 9.4 months (range 1 to 24). Pharmacological therapy was unsuccessful despite the combination of antiarrhythmic drugs. The tachycardia was incessant with a density > 85% by 24-hour Holter monitoring; one patient developed tachycardia-induced cardiomyopathy. All children underwent successful radiofrequency catheter ablation, mean 5 ± 3 applications (range 1 to 8) with a single session and with no complications. After a mean follow-up of 24 ± 16 months, all patients were asymptomatic and recurrence-free without antiarrhythmic treatment. CONCLUSIONS: Coumel tachycardia is clinically persistent and usually refractory to antiarrhythmic treatment with substantial risk of tachycardia-mediated cardiomyopathy. Catheter ablation is effective and safe in children; thus, it should be indicated promptly and based on individual selection.

INTRODUCCIÓN: La taquicardia de Coumel es una forma poco frecuente de taquicardia supraventricular que suele presentarse en lactantes. Es una taquicardia mediada por una vía accesoria de conducción lenta retrógrada que explica el patrón ECG clásico con intervalo RP' largo y ondas P negativas en las derivaciones II, III y aVF. En este trabajo se describe el curso clínico y el manejo de la taquicardia de Coumel en niños. CASO CLÍNICO: Se llevó a cabo una revisión retrospectiva de cinco pacientes pediátricos consecutivos, con una media de edad de 11 ± 3 años (intervalos 6 a 14). El primer episodio de taquicardia 10.4 ± 4.8 años con evolución de 7.4 ± 9.4 meses. El tratamiento farmacológico fue ineficaz a pesar de la combinación de antiarrítmicos. La taquicardia era incesante con una densidad > 85% por Holter-24h; un paciente desarrolló miocardiopatía inducida por taquicardia. Todos los niños fueron sometidos a ablación con catéter y radiofrecuencia con éxito, y un promedio de 5 ± 3 aplicaciones en una sola sesión y sin complicaciones. Después de un seguimiento de 24 ± 16 meses, todos los pacientes fueron asintomáticos y libres de recurrencia sin tratamiento antiarrítmico. CONCLUSIONES: La taquicardia de Coumel es clínicamente persistente y generalmente refractaria al tratamiento antiarrítmico con un riesgo sustancial de miocardiopatía mediada por taquicardia. La ablación con catéter es eficaz y segura en niños, por lo que debe indicarse de forma temprana y en lactantes de una selección individual.

A Case of Non-Tachycardic Atrial Fibrillation Whose Left Ventricular Systolic Dysfunction Improved After Catheter Ablation.

It is difficult to identify the causes and optimal treatment of heart failure (HF) in patients with atrial fibrillation (AF) and HF with reduced ejection fraction (EF) (HFrEF). Tachyarrhythmia can cause left ventricular (LV) systolic dysfunction called tachycardia-induced cardiomyopathy (TIC). In patients with TIC, conversion to sinus rhythm may lead to improvement in LV systolic dysfunction. However, it is unclear whether we should try to convert patients with AF without tachycardia to sinus rhythm. A 46-year-old man with chronic AF and HFrEF came to our hospital. His New York Heart Association (NYHA) classification was class II. The blood test showed a brain natriuretic peptide of 105 pg/mL. Electrocardiogram (ECG) and 24-h ECG showed AF without tachycardia. Transthoracic echocardiography (TTE) showed left atrial (LA) dilatation, LV dilatation, and diffuse LV hypokinesis (EF was 40%). Although he was optimized medically, NYHA classification II persisted. Therefore, he underwent direct current cardioversion and catheter ablation. After his AF converted to a sinus rhythm of heart rate (HR) 60 - 70 beats per minute (bpm), TTE showed improvement in LV systolic dysfunction. We gradually reduced oral medications for arrhythmia and HF. We subsequently succeeded in discontinuing all medications 1 year after catheter ablation. TTE performed between 1 and 2 years after catheter ablation showed normal LV function and normal cardiac size. During the 3 years of follow-up, there was no recurrence of AF, and he was not readmitted to the hospital. This patient showed the effectiveness of converting AF to sinus rhythm in patients without tachycardia.

Right Heart Structure and Function after Electrical Cardioversion for Atrial Fibrillation.

INTRODUCTION: Atrial fibrillation (AF) adversely impacts right ventricular (RV) and right atrial (RA) structure and function. There are limited data on these changes after electrical cardioversion (ECV) and the relative contribution of heart rate to evaluate the immediate (1-2 h) and short-term (4-6 weeks) changes in right cardiac chamber dimensions and RV function after ECV in patients with persistent AF. METHODS: Right cardiac chamber dimensions and RV function were measured in 64 patients using transthoracic echocardiography 1-2 h before, immediately after, and 4-6 weeks after ECV. Associations between changes in right-heart measures and rhythm status at follow-up were assessed using linear regression models. RESULTS: For patients who remained in sinus rhythm 4-6 weeks after ECV (n = 48), median fractional area change (FAC) at baseline, immediately after ECV, and 4-6 weeks after ECV were 39 (Q1:35, Q3:42) %, 42 (Q1:39, Q3:46) %, 46 (Q1:43, Q3:49) % (p < 0.01); median tricuspid annular plane systolic excursion (TAPSE) values at the same time points were 18 (Q1:17, Q3:20) mm, 20 (Q1:18, Q3:23) mm, and 24 (Q1:22, Q3:26) mm (p < 0.01), respectively. There was no significant difference in RV end systolic area and RA volume index before and after ECV. However, RV end systolic area and RA volume index decreased significantly after 4-6 weeks from a median of 10 (Q1:8, Q3:13) cm2 to 8 (Q1:7, Q3:10) cm2 (p < 0.01), and from a median of 30 (Q1:24, Q3:36) mL/m2 to 24 (Q1:20, Q3:27) mL/m2 (p < 0.01). Changes in TAPSE were significantly associated with sinus rhythm at follow-up (p = 0.027), changes in FAC showed a strong trend to association with sinus rhythm (p = 0.053), and this was not true for RA measures (p = 0.64). CONCLUSIONS: Among AF patients who remained in sinus rhythm after ECV, RV function improved immediately after ECV with further improvement at 4-6 weeks following sinus rhythm restoration.

Echocardiographic pattern of left ventricular function recovery in tachycardia-induced cardiomyopathy patients.

AIMS: Tachycardia-induced cardiomyopathy (TCM) represents a partially reversible type of cardiomyopathy (CM) that is often underdiagnosed and cardiac chamber remodelling in TCM remains incompletely understood. We aim to explore differences in the dimensions of the left ventricle and functional recovery in patients with TCM compared with patients with other forms of CM. METHODS AND RESULTS: We identified patients with reduced ejection fraction (≤50%) and/or atrial fibrillation or flutter with a left ventricular ejection fraction that improved from baseline (≥15% in left ventricular ejection fraction at follow-up or normalization of cardiac function with at least 10% improvement). Patients were then divided into two groups: (A) TCM patients and (B) patients with other forms of CM (controls). Two hundred thirty-eight patients were included (31% female, 70 years median age), 127 patients had TCM, and 111 had other forms of CM. Patients with TCM did not significantly improve indexed left ventricular volume (LVEDVI) after treatment (60 [45, 84] mL/m2 versus 56 [45, 70] mL/m2 , P = ns) compared with controls (67 [54, 81] mL/m2 versus 52 [42, 69] mL/m2 , P < 0.001). Patients with TCM patients had significantly worse fractional shortening at baseline than controls (15.5 [12, 23] vs. 20 [13, 30], P = 0.01) and higher indexed left atrial volume (LAVI) at baseline than controls (48 [37, 58] vs. 41 [33, 51], P = 0.01) that remained dilated at follow-up (follow-up LAVI 41 [33, 52] mL/m2 ). Good predictors of TCM were: normal LVEDVI (LVEDVI < 58 mL/m2 (M) and < 52 mL/m2 (F)) (odds ratio [OR] 5.2; 95% confidence interval [CI] 2.2-13.3, P < 0.001), fractional shortening < 30% (OR 3.5; 95% CI 1.4-9.2, P = 0.009), LAVI >40 mL/m2 (OR 3.4; 95% CI 1.6-7.3, P = 0.001) and normal wall thickness left ventricle (OR 3.2; 95% CI 1.4-7.8, P = 0.008). 54% of patients with TCM demonstrated diastolic dysfunction at follow-up, without differences from controls (54% vs. 43%, P = ns). 21% of patients with TCM showed persistent heart failure symptoms at follow-up compared with 4.5% of controls, P = 0.004. CONCLUSIONS: TCM patients have a specific pattern of functional recovery with persistent remodelling of the left atria and left ventricle. Several echocardiographic parameters might help identify TCM before treatment.