Kristi H. Monahan

Clinical Presentation, Investigation, and Management of Pulmonary Vein Stenosis Complicating Ablation for Atrial Fibrillation

Background—Although segmental or circumferential ablation is effective in eliminating pulmonary vein (PV)–mediated atrial fibrillation (AF), this procedure may be complicated by the occurrence of PV stenosis. Methods and Results—To establish the clinical presentation, diagnostic manifestations, and interventional management of PV stenosis, 23 patients with stenosis of 34 veins complicating ablation of AF were evaluated. Each patient became symptomatic 103±100 days after undergoing ablation. In 8 veins, the ablation producing the PV stenosis was a repeated procedure for continued AF. Nineteen patients presented with dyspnea on exertion, 7 with dyspnea at rest, 9 with cough, and 6 with chest pain. On multirow spiral computed tomography examination, the narrowest lumen of the affected PVs measured 3±2 mm compared with 13±3 mm at baseline (P≤0.001). The relative perfusion of affected lung segments on isotope scans was reduced to 4±3% of total perfusion compared with 22±10% in unaffected segments. At percutaneous intervention, these veins showed 80±13% stenosis, with a mean gradient of 12±5 mm Hg. This was significantly reduced to a residual stenosis of 9±8% (P≤0.001) and a residual gradient of 3±4 mm Hg (P≤0.001). Twenty veins were treated with balloon dilatation alone, whereas 14 veins were stented with standard 10-mm-diameter bare-metal stents. Although the symptomatic response was nearly immediate and impressive, 14 patients developed in-stent or in-segment restenosis, requiring repeated interventions in 13. Conclusions—Percutaneous intervention produces rapid and dramatic symptom relief in patients with highly symptomatic PV stenosis after radiofrequency ablation for AF. Nevertheless, alternative treatment methods will be required to decrease recurrent in-stent or in-segment restenosis.

Pulmonary Vein Stenosis Complicating Ablation for Atrial Fibrillation: Clinical Spectrum and Interventional Considerations

Ablation procedures for atrial fibrillation are being performed with increasing frequency. One of the most serious complications is the development of pulmonary vein stenosis, which occurs in 1% to 3% of current series. The presentation of pulmonary vein stenosis varies widely. The majority of patients are symptomatic although specific referral bias patterns can affect this. Symptoms may include dyspnea or hemoptysis or may be consistent with bronchitis. These symptoms are affected by the number of stenotic veins as well as the severity of the stenosis. The more severe the stenosis and the greater number of stenosed veins result in more symptoms. Because of the variability in symptoms, clinicians must have heightened sensitivity to the presence of the condition. Diagnostic tests of value include magnetic resonance angiography and computed tomography. Although echocardiography has been used, it does not usually provide adequate assessment. Progression of stenosis is unpredictable and may be rapid. The specific anatomy of the stenosis varies widely and affects management. Because of the presence of antral fusion of the origin of the left superior and left inferior pulmonary vein, a stenosis involving 1 or the other can impinge and affect outcome. In this setting, bifurcation techniques familiar to interventional cardiology are very helpful. Controversy currently exists about the optimal treatment approach. The use of balloons and larger stents (approximately 10 mm) results in more optimal results than just balloon angioplasty alone; however, even with stent implantation, recurrent restenosis may occur in 30% to 50% of patients. Follow-up of these patients typically involves computed tomography imaging to document restenosis. If significant restenosis is identified, it should be treated promptly because of the potential for progression to total occlusion.

Dynamic intraventricular obstruction during dobutamine stress echocardiography. A new observation.

BackgroundThe implications of hypotension occurring during dobutamine stress echocardiography have not been elucidated. We observed in some patients that hyperdynamic left ventricular function developed during dobutamine stress echocardiography and hypothesized that intracavitary obstruction was occurring and might account for hypotension in some patients. Methods and ResultsFifty-seven consecutive patients undergoing dobutamine stress echocardiography underwent pulsed-wave and continuous-wave Doppler examination of the left ventricular cavity at rest and at peak dobutamine infusion. The development of an intraventricular gradient with dobutamine stress was defined as a late-peaking left ventricular Doppler velocity profile that exceeded basal velocity by at least 1 m/sec. During dobutamine stress testing, left ventricular outflow velocity or intracavitary velocity increased in all patients. Obstruction occurred in 12 patients (21%, group 1). Group 2 was the remaining 45 patients. Peak velocities in group 1 ranged from 2.0 to 5.0 m/sec (mean, 3.5 m/sec), and the mean increase from velocity at rest was 2.3 m/sec. The mean change in systolic blood pressure was significantly lower in patients in group 1 (−15 versus 4 mm Hg, p=0.02). When the 18 patients with an ischemic response to stress testing (evidenced by new or worsening wall motion abnormalities) were excluded from analysis, systolic blood pressure response was still significantly different for the two groups (−19 versus 2 mm Hg, p=0.03). ConclusionsDynamic left ventricular obstruction is a new observation; it may develop frequently in patients undergoing dobutamine stress echocardiography. Obstruction rather than ischemia may explain a decrease in blood pressure during dobutamine stress echocardiography.

Long-Term Quality of Life After Ablation of Atrial Fibrillation The Impact of Recurrence, Symptom Relief, and Placebo Effect

OBJECTIVES We sought to determine the relationship between atrial fibrillation (AF) ablation efficacy, quality of life (QoL), and AF-specific symptoms at 2 years. BACKGROUND Although the primary goal of AF ablation is QoL improvement, this effect has yet to be demonstrated in the long term. METHODS A total of 502 symptomatic AF ablation recipients were prospectively followed for recurrence, QoL, and AF symptoms. RESULTS In 323 patients with 2 years of follow-up, 72% achieved AF elimination off antiarrhythmic drugs (AADs), 15% achieved AF control with AADs, and 13% had recurrent AF. The physical component summary scores of the Medical Outcomes Study Short Form 36 increased from 58.8 +/- 20.1 to 76.2 +/- 19.2 (p < 0.001) and the mental component summary scores of the Short Form 36 increased from 65.3 +/- 18.6 to 79.8 +/- 15.8 (p < 0.001). Post-ablation QoL improvements were noted across ablation outcomes, including recurrent AF (change in physical component summary: 12.1 +/- 19.7 and change in mental component summary: 9.7 +/- 17.9), with no significant differences in QoL improvement across 3 ablative efficacy outcomes. However, in 103 patients who completed additional assessment with Mayo AF Symptom Inventories (on a scale of 0 to 48), those with AF elimination off AADs had a change in AF symptom frequency score of -9.5 +/- 6.3, which was significantly higher than those with AF controlled with AADs (-5.6 +/- 3.8, p = 0.03) or those with recurrent AF (-3.4 +/- 8.4, p = 0.02). Independent predictors of limited QoL improvement included higher baseline QoL, obesity, and warfarin use at follow-up. CONCLUSIONS AF ablation produces sustained QoL improvement at 2 years in patients with and without recurrence. AF-specific symptom assessment more accurately reflects ablative efficacy.

Success of Ablation for Atrial Fibrillation in Isolated Left Ventricular Diastolic Dysfunction: A Comparison to Systolic Dysfunction and Normal Ventricular Function

Background— The efficacy of radiofrequency ablation for atrial fibrillation (AF) in patients with left ventricular (LV) systolic dysfunction and isolated diastolic dysfunction is uncertain. Methods and Results— A prospective cohort of patients with normal and abnormal LV function underwent ablation for antiarrhythmic drug (AAD)-refractory AF. Three groups were compared: 111 patients with systolic dysfunction, defined as LV ejection fraction (LVEF) ≤40%; 157 patients with isolated diastolic dysfunction but preserved LVEF ≥50%; and 100 patients with normal LV function. The primary end point was AAD-free AF elimination at 1 year after ablation. This end point was achieved in 62% of patients with systolic dysfunction, 75% of those with diastolic dysfunction, and 84% of controls ( P =0.007). AF control on or off AADs was achieved in 76% of patients with systolic dysfunction, 85% of those with diastolic dysfunction, and 89% of controls ( P =0.08). In the systolic dysfunction group, 49% experienced an increase in LVEF by ≥5% after ablation, of which 64% achieved normal LVEF. In the diastolic dysfunction group, 30% of patients demonstrated at least 1 grade improvement in diastolic dysfunction. Multivariable analysis demonstrated an increased relative risk of arrhythmia recurrence of 1.8 (95% CI, 1.1 to 3.1; P =0.02) in systolic dysfunction and 1.7 (1.0 to 2.7; P =0.04) in isolated diastolic dysfunction compared with normal function. Conclusions— Although an ablative approach for AF in patients with systolic or diastolic dysfunction is associated with an increased long-term recurrence risk, there is potential for substantial quality-of-life improvement and LV functional benefit.Background— The efficacy of radiofrequency ablation for atrial fibrillation (AF) in patients with left ventricular (LV) systolic dysfunction and isolated diastolic dysfunction is uncertain. Methods and Results— A prospective cohort of patients with normal and abnormal LV function underwent ablation for antiarrhythmic drug (AAD)-refractory AF. Three groups were compared: 111 patients with systolic dysfunction, defined as LV ejection fraction (LVEF) ⩽40%; 157 patients with isolated diastolic dysfunction but preserved LVEF ≥50%; and 100 patients with normal LV function. The primary end point was AAD-free AF elimination at 1 year after ablation. This end point was achieved in 62% of patients with systolic dysfunction, 75% of those with diastolic dysfunction, and 84% of controls (P=0.007). AF control on or off AADs was achieved in 76% of patients with systolic dysfunction, 85% of those with diastolic dysfunction, and 89% of controls (P=0.08). In the systolic dysfunction group, 49% experienced an increase in LVEF by ≥5% after ablation, of which 64% achieved normal LVEF. In the diastolic dysfunction group, 30% of patients demonstrated at least 1 grade improvement in diastolic dysfunction. Multivariable analysis demonstrated an increased relative risk of arrhythmia recurrence of 1.8 (95% CI, 1.1 to 3.1; P=0.02) in systolic dysfunction and 1.7 (1.0 to 2.7; P=0.04) in isolated diastolic dysfunction compared with normal function. Conclusions— Although an ablative approach for AF in patients with systolic or diastolic dysfunction is associated with an increased long-term recurrence risk, there is potential for substantial quality-of-life improvement and LV functional benefit.

Substrate and Procedural Predictors of Outcomes After Catheter Ablation for Atrial Fibrillation in Patients with Hypertrophic Cardiomyopathy

Background: Hypertrophic cardiomyopathy (HCM) is often accompanied by atrial fibrillation (AF) due to diastolic dysfunction, elevated left atrial pressure, and enlargement. Although catheter ablation for drug‐refractory AF is an effective treatment, the efficacy in HCM remains to be established.

Catheter Ablation for Atrial Fibrillation in Patients With Obesity

Background— Obesity is a risk factor for atrial fibrillation and other cardiovascular conditions. Our objective was to determine whether catheter-based ablation effectively treated atrial fibrillation in obese patients. Methods and Results— Five hundred twenty-three consecutive patients with symptomatic, medication-refractory atrial fibrillation underwent catheter ablation. Patients were grouped by body mass index (lean, <25 kg/m2; overweight, 25 to 29.9 kg/m2; obese, ≥30 kg/m2). Outcome and quality of life were measured with a general health survey (Medical Outcomes Study 36-item Short-Form General Health Survey [SF-36]); patients were assessed before ablation and at 3 and 12 months after the procedure. Two hundred twenty-eight study patients (44%) were overweight, and 201 (38%) were obese. Twelve months after curative ablation, 72% of patients were free of atrial fibrillation without the use of antiarrhythmic agents; 84% were arrhythmia free when those receiving medication were included. Atrial fibrillation was eliminated in 75%, 72%, and 70% of the lean, overweight, and obese patients, respectively, at 12 months (P=0.41, trend test). SF-36 scores were lower for patients with higher body mass index (P<0.05) at baseline. SF-36 scores improved in every functional domain for all body mass index groups after ablation. The mean SF-36 total physical score increased from 59±20 at baseline to 77±19 in 12 months (P<0.001). The total mental health score improved from 66±18 to 79±16 in 12 months (P<0.001). Conclusions— Catheter ablation of atrial fibrillation was effective in obese patients. Coexistence of atrial fibrillation and obesity indicated lower SF-36 scores, but the improvement in quality of life was consistent across all body mass index categories.

Differentiating Atrioventricular Nodal Reentrant Tachycardia from Junctional Tachycardia: Novel Application of the Delta H-A Interval

Introduction: Junctional tachycardia (JT) and atrioventricular nodal reentrant tachycardia (AVNRT) can be difficult to differentiate. Yet, the two arrhythmias require distinct diagnostic and therapeutic approaches. We explored the utility of the delta H‐A interval as a novel technique to differentiate these two tachycardias.

Severe Pulmonary Vein Stenosis Resulting From Ablation for Atrial Fibrillation: Presentation, Management, and Clinical Outcomes.

Background: The frequency of pulmonary vein stenosis (PVS) after ablation for atrial fibrillation has decreased, but it remains a highly morbid condition. Although treatment strategies including pulmonary vein dilation and stenting have been described, the long-term impacts of these interventions are unknown. We evaluated the presentation of severe PVS, and examined the risk for restenosis after intervention using either balloon angioplasty (BA) alone or BA with stenting. Methods: This was a prospective, observational study of 124 patients with severe PVS evaluated between 2000 and 2014. Results: All 124 patients were identified as having severe PVS by computed tomography in 219 veins. One hundred two patients (82%) were symptomatic at diagnosis. The most common symptoms were dyspnea (67%), cough (45%), fatigue (45%), and decreased exercise tolerance (45%). Twenty-seven percent of patients experienced hemoptysis. Ninety-two veins were treated with BA, 86 were treated with stenting, and 41 veins were not treated. A 94% acute procedural success rate was observed and did not differ by initial management. Major procedural complications occurred in 4 of the 113 patients (3.5%) who underwent invasive assessment, and minor complications occurred in 15 patients (13.3%). Overall, 42% of veins developed restenosis including 27% of veins (n=23) treated with stenting and 57% of veins (n=52) treated with BA. The 3-year overall rate of restenosis was 37%, with 49% of BA-treated veins and 25% of stented veins developing restenosis (hazard ratio, 2.77; 95% confidence interval, 1.72–4.45; P<0.001). After adjustment for age, CHA2DS2-VASc score, hypertension, and the time period of the study, there was still a significant difference in the risk of restenosis for BA versus stenting (hazard ratio, 2.46; 95% confidence interval, 1.47–4.12; P<0.001). Conclusions: The diagnosis of PVS is challenging because of nonspecific symptoms and the need for dedicated pulmonary vein imaging. There is no difference in acute success by type of initial intervention; however, stenting significantly reduces the risk of subsequent pulmonary vein restenosis in comparison with BA.

Effect of Radiofrequency Ablation of Atrial Flutter on the Natural History of Subsequent Atrial Arrhythmias

Introduction: Patients with atrial flutter (AFL) treated medically are at high risk for subsequent development of atrial fibrillation (AF). Whether curative radiofrequency ablation of AFL can modify the natural history of arrhythmia progression is not clear. We aimed to determine whether ablation of AFL decreases the subsequent development of AF in patients without previous AF.