2. Implantation of a Biventricular Implantable Cardioverter-Defibrillator Followed by Catheter Ablation in a Patient with Dilated Cardiomyopathy and Permanent Atrial Fibrillation

Published on 02/03/2015 by admin

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Last modified 22/04/2025

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History

The patient has dilated cardiomyopathy with an initial left ventricular ejection fraction (LVEF) of 25%, permanent atrial fibrillation (AF), and the cardiovascular risk factors of obesity (body mass index 32 kg/m²) and arterial hypertension.
The diagnosis of nonischemic dilated cardiomyopathy was established 1 year previously after angiographic exclusion of significant coronary artery disease, and medical heart failure therapy was initiated. Additionally, an antiarrhythmic treatment with amiodarone and an oral anticoagulation with phenprocoumon were initiated because of highly symptomatic paroxysmal AF mainly manifesting as debilitating palpitations. The amiodarone therapy, however, had to be terminated as a result of drug-induced hyperthyroidism after 3 months of treatment. Over the past several months, paroxysmal AF progressed to less symptomatic persistent AF, and after recent electrical cardioversion had failed to restore sinus rhythm, AF was considered permanent because the decision was made to cease further attempts of rhythm control interventions and to continue with a rate control strategy with metoprolol and digitoxin.2
The patient arrived for treatment with slowly progressive breathlessness, fatigue, marked limitation of physical activity corresponding to New York Heart Association (NYHA) functional class III, and ankle swelling despite optimal medical heart failure treatment. He also reports recurrent episodes of irregular heart action.

Current Medications

The patient’s current medications are metoprolol 95 mg twice daily; phenprocoumon with a target international normalized ratio of 2.5 (range 2.0 to 3.0); digitoxin 0.07 mg once daily; torasemide 10 mg twice daily; ramipril 10 mg once daily; and spironolactone 25 mg once daily.

Current Symptoms

The patient demonstrated progressive breathlessness, marked limitation of physical activity (NYHA functional class III), fatigue, severely reduced exercise capacity, mildly symptomatic irregular heart action, and recurrent ankle swelling. Anginal pain, dizziness, and syncopal events were denied.

Physical Examination

Laboratory Data

Electrocardiogram

Findings

The electrocardiogram recorded atrial fibrillation with a heart rate of about 55 bpm, normal QRS axis, left bundle branch block with a QRS duration of 150 ms, QT interval duration of 440 ms, and secondary repolarization abnormalities (Figure 2-1).

Chest Radiograph

Findings

The major radiograph findings on posteroanterior view were global cardiac enlargement, slight pleural effusions, and subtle pulmonary congestion (Figure 2-2).

Echocardiogram

Findings

Transthoracic 2-dimensional echocardiography revealed LV dilation (LV end-diastolic volume 222 mL, LV end-diastolic diameter 66 mm) and severe systolic dysfunction with a LVEF of 35% (Figure 2-3). Both the parasternal long-axis view and the 4-chamber view demonstrated a substantial dilation of the left atrium (50 mm in the parasternal long axis) (Figure 2-4). Clinically relevant valvular heart disease could be excluded.
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FIGURE 2-1 Surface 12-lead electrocardiogram, recording speed 50 mm/sec (see text for interpretation).

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FIGURE 2-2 Chest radiograph, posteroanterior view (see text for interpretation).

Focused Clinical Questions and Discussion Points

Question

Does evidence from clinical trials exist that supports cardiac resynchronization therapy (CRT) in patients with systolic heart failure, wide QRS complex, and permanent AF?

Discussion

Patients with AF are highly underrepresented in randomized trials of CRT. This is in contrast to routine practice because more than 20% of patients undergoing CRT have episodes of AF.3 A meta-analysis of prospective cohort studies demonstrated that patients with persistent or permanent AF had a substantial benefit from CRT with respect to cardiac performance and functional outcomes.11 Moreover, in the Multicentre Longitudinal Observational Study, mortality rates of patients with sinus rhythm or permanent AF who had undergone CRT were similar during a median follow-up period of 34 months.6 Current guidelines of the European Society of Cardiology (ESC) recommend that implantation of a biventricular pacemaker or implantable cardioverter-defibrillator (ICD) should be considered to reduce morbidity in patients with permanent AF, NYHA functional class III/IV, a LVEF of 35% or less, an intrinsic QRS width of 130 ms or greater (120 ms or greater according to recently published 2013 ESC guidelines), and/or pacemaker dependency with frequent ventricular pacing (class IIa recommendation).1,4
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FIGURE 2-3 Two-dimensional transthoracic echocardiographic still-frame images from the 4-chamber view during diastole (A) and systole (B) (see text for interpretation).

Question

Should an atrial lead be implanted in patients with permanent AF undergoing CRT device implantation?

Discussion

AF is defined as permanent if cardioversion fails to restore sinus rhythm or if no rhythm control interventions are pursued.2,7 It might be argued that an atrial lead is not required in these patients and that additional atrial lead placement would unnecessarily increase the risk for perioperative complications. In a multicenter, retrospective, longitudinal study, 330 patients with a CRT device and permanent AF were followed for a median of 42 months.7 During the study period, spontaneous sinus rhythm resumption occurred in approximately 10% of patients. A post-CRT QRS of 150 ms or less, a LV end-diastolic diameter of 65 mm or less, a left atrial diameter of 50 mm or less, and AV junction ablation were predictors of sinus rhythm resumption.
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FIGURE 2-4 Two-dimensional transthoracic echocardiographic still-frame images from the parasternal long axis (A) and the 4-chamber view (B) (see text for interpretation).

Question

Are ablative strategies, that is, AV node ablation or left atrial catheter ablation, able to improve outcome in patients with CRT and persistent or permanent AF?

Discussion

The rationale for AV node ablation in patients with CRT and permanent AF is to control ventricular rate to ensure a maximum biventricular pacing time and obtain a regular ventricular rhythm, because the benefit of CRT depends on a 100% biventricular pacing rate and RR-interval irregularity is associated with worsening of cardiac function.9,10 In a study by Gasparini and colleagues including 673 patients with heart failure and CRT, patients with permanent AF demonstrated substantial and sustained long-term improvements in LV performance and functional capacity similar to those in patients with sinus rhythm only if ablation of the AV junction had been performed.5 Additionally, it was demonstrated that AF patients with AV junction ablation had a significantly lower all-cause mortality rate in contrast to patients with AF with medical rate control only.6 Current ESC guidelines state that AV nodal ablation may be required to ensure adequate pacing.1,4 The role of AF catheter ablation in patients with no or moderate cardiac disease is well established, especially in those with paroxysmal AF.2 Catheter ablation of patients with systolic heart failure, however, is less well established. In the Pulmonary Vein Antrum Isolation vs. AV Node Ablation with Biventricular Pacing for Treatment of Atrial Fibrillation in Patients with Congestive Heart Failure (PABA-CHF) trial, 81 patients with drug-refractory AF (∼50% had persistent or long-standing persistent AF) and a LVEF of 40% or less were randomly assigned to pulmonary vein isolation (plus additional linear lesions) or AV node ablation with biventricular pacing.8 After 6 months, 71% of patients in the catheter ablation group were free from AF without concomitant antiarrhythmic drug treatment. Catheter ablation was superior to AV node ablation and CRT with respect to an improvement in LVEF, functional capacity, and quality of life. The 2012 Heart Rhythm Society, European Heart Rhythm Association, and European Cardiac Arrhythmia Society Expert Consensus Statement on Catheter and Surgical Ablation of Atrial Fibrillation states that according to current studies, catheter ablation may be a reasonable treatment option in strictly selected patients with heart failure.2

Final Diagnosis

The patient’s final diagnoses were highly symptomatic dilated cardiomyopathy with a LVEF of 35% and a wide QRS complex, and permanent AF.

Plan of Action

The patient fulfilled the criteria for CRT according to current guidelines (LVEF of 35%, NYHA functional class III despite optimal medical treatment, and QRS width of 150 ms).1,4 Therefore, implantation of a biventricular ICD device with an atrial lead was scheduled after cardiac recompensation.

Intervention

A biventricular ICD was successfully implanted.

Outcome

Six months after CRT implantation, slight improvement of cardiac function was found on echocardiography. This improvement, however, did not translate into a clinical benefit because the patient remained highly symptomatic (NYHA functional class III) despite effective CRT (biventricular pacing rate approximately 98%). Therefore a rhythm control strategy was reconsidered and the patient was scheduled for left atrial catheter ablation. This decision was based on data from the PABA-CHF study showing that sinus rhythm could be restored in a considerable number of patients despite distinct dilation of the left atrium (mean left atrial diameter in the pulmonary isolation group measured 49 ± 5 mm).8
After transseptal access to the left atrium and registration of a CT-derived three-dimensional model of the left atrium in the electroanatomic mapping system (Figure 2-5), circumferential ablation lines were placed around the ipsilateral pulmonary vein pairs at the antral level to achieve complete pulmonary vein isolation (i.e., bidirectional conduction block). Subsequently, a bipolar voltage map of the left atrium was created to identify potential AF triggers or substrate for the perpetuation of AF. The voltage map, however, revealed exclusively voltages greater than 0.5 mV which by definition represent normal tissue. Thus no further substrate modification was performed. At the end of the procedure, sinus rhythm was restored and no sustained atrial arrhythmia could be induced by atrial burst pacing.
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FIGURE 2-5 Anterior-posterior (A) and posterior-anterior (B) view of a three-dimensional model of the left atrium and the pulmonary veins acquired by preprocedural computed tomography and registered into the electroanatomic mapping system. Red dots indicate the circumferential ablation line, purple areas represent bipolar voltages with an amplitude greater than 0.5 mV (normal voltage by definition).

Findings

Up to 6 months after catheter ablation, no mode-switch episodes indicating AF recurrences or atrial tachycardias have been observed during routine interrogations. Functional status improved significantly by one NYHA functional class, and LVEF increased to 40%.

Selected References

1. Brignole M., Auricchio A., Baron-Esquivias G. et al. 2013 ESC guidelines on cardiac pacing and cardiac resynchronization therapy. Eur Heart J. 2013;34:2281–2329.

2. Calkins H., Kuck K.H., Cappato R. et al. 2012 HRS/EHRA/ECAS Expert Consensus Statement on Catheter and Surgical Ablation of Atrial Fibrillation: recommendations for patient selection, procedural techniques, patient management and follow-up, definitions, endpoints, and research trial design. Europace. 2012;14:528–606.

3. Dickstein K., Bogale N., Priori S. et al. The European cardiac resynchronization therapy survey. Eur Heart J. 2009;30:2450–2460.

4. Dickstein K., Vardas P.E., Auricchio A. et al. 2010 Focused Update of ESC Guidelines on device therapy in heart failure: an update of the 2008 ESC Guidelines for the diagnosis and treatment of acute and chronic heart failure and the 2007 ESC Guidelines for cardiac and resynchronization therapy. Developed with the special contribution of the Heart Failure Association and the European Heart Rhythm Association. Europace. 2010;12:1526–1536.

5. Gasparini M., Auricchio A., Regoli F. et al. Four-year efficacy of cardiac resynchronization therapy on exercise tolerance and disease progression: the importance of performing atrioventricular junction ablation in patients with atrial fibrillation. J Am Coll Cardiol. 2006;48:734–743.

6. Gasparini M., Auricchio A., Metra M. et al. Multicentre Longitudinal Observational Study (MILOS) Group: Long-term survival in patients undergoing cardiac resynchronization therapy: the importance of performing atrio-ventricular junction ablation in patients with permanent atrial fibrillation. Eur Heart J. 2008;29:1644–1652.

7. Gasparini M., Steinberg J.S., Arshad A. et al. Resumption of sinus rhythm in patients with heart failure and permanent atrial fibrillation undergoing cardiac resynchronization therapy: a longitudinal observational study. Eur Heart J. 2010;31:976–983.

8. Khan M.N., Jaïs P., Cummings J. et al. PABA-CHF Investigators. Pulmonary-vein isolation for atrial fibrillation in patients with heart failure. N Engl J Med. 2008;359:1778–1785.

9. Koplan B.A., Kaplan A.J., Weiner S. et al. Heart failure decompensation and all-cause mortality in relation to percent biventricular pacing in patients with heart failure: is a goal of 100% biventricular pacing necessary? J Am Coll Cardiol. 2009;53:355–360.

10. Melenovsky V., Hay I., Fetics B.J. et al. Functional impact of rate irregularity in patients with heart failure and atrial fibrillation receiving cardiac resynchronization therapy. Eur Heart J. 2005;26:705–711.

11. Upadhyay G.A., Choudhry N.K., Auricchio A. et al. Cardiac resynchronization in patients with atrial fibrillation: a meta-analysis of prospective cohort studies. J Am Coll Cardiol. 2008;52:1239–1246.

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