Sinus Node Sparing Hybrid Thoracoscopic Ablation Outcomes in Patients with Inappropriate Sinus Tachycardia (SUSRUTA-IST) Registry.

BACKGROUND: Medical treatment of inappropriate sinus tachycardia (IST) remains suboptimal. Radiofrequency sinus node (RF-SN) ablation has poor success and higher complication rates. OBJECTIVE: We aimed to compare clinical outcomes of the novel SN sparing hybrid ablation technique with those of RF-SN modification for IST management. METHODS: This is a multicenter prospective registry comparing the SN sparing hybrid ablation strategy with RF-SN modification. The hybrid procedure was performed using an RF bipolar clamp, isolating superior vena cava/inferior vena cava with the creation of a lateral line across the crista terminalis while sparing the SN region (identified by endocardial 3-dimensional mapping). RF-SN modification was performed by endocardial and/or epicardial mapping and ablation at the site of earliest atrial activation. RESULTS: Of the 100 patients (hybrid ablation group, n = 50; RF-SN group, n = 50), 82% were women, and the mean age was 22.8 years. Normal sinus rhythm and rate were restored in all patients in the hybrid group (vs 84% in the RF-SN group; P = .006). Hybrid ablation was associated with significantly better improvement in mean daily heart rate and peak 6-minute walk heart rate compared with RF-SN ablation. The RF-SN group had a significantly higher rate of redo procedures (100% vs 8%; P < .001), phrenic nerve injury (14% vs 0%; P = .012), lower acute pericarditis (48% vs 92%; P < .0001), permanent pacemaker implantation (50% vs 4%; P < .0001) than did the hybrid ablation group. CONCLUSION: The novel sinus node sparing hybrid ablation procedure appears to be more efficacious and safer in patients with symptomatic drug-resistant IST with long-term durability than RF-SN ablation.

Ablation therapy of postural orthostatic tachycardia syndrome, inappropriate sinus tachycardia and primary electrical diseases: new insights in invasive treatment options in severely symptomatic patients.

Achieving the goal management of some arrhythmic syndromes can be challenging; medical treatment for inappropriate sinus tachycardia (IST) and postural orthostatic tachycardia syndrome (POTS) may be ineffective, necessitating multidisciplinary team treatment. Implantable defibrillator devices (ICDs), along with anti-arrhythmic drugs (AADs), remain the first-line treatment for primary electrical diseases that pose a risk of sudden cardiac death (SCD). Ablation of the arrhythmogenic substrate is not always suggested in patients with these pathologies, but it may be a valuable support for reducing arrhythmic burden, improving quality of life, and treating pathologies that are resistant to pharmacological treatment; however, this option is not often considered due to the potential risks associated with an invasive approach. Minimally invasive hybrid ablation in these syndromes, such as a hybrid thoracoscopic approach and the use of non-invasive mapping systems, reduces post-surgery complications and ensures the best possible outcome for the patient.

Minimally invasive thoracoscopic surgery is an effective approach for treating inappropriate sinus tachycardia.

INTRODUCTION: Inappropriate sinus tachycardia (IST) is characterized by increased heart rate out of proportion to normal physiologic demand. IST ablation is challenging for the electrophysiology community due to the epicardial location of the sinus node and the risk of phrenic nerve (PN) injury during catheter ablation. In this study, we investigated the safety and efficacy of a minimally invasive thoracoscopic surgery for elimination of IST. METHODS: Patients with IST who failed medical therapy or endocardial ablation underwent minimally invasive thoracoscopic epicardial ablation. Epicardial activation mapping was performed to identify the earliest activation site and any possible migration of earliest activation along the lateral right atrium. The PN in each patient was protected by a pericardial retraction suture. RESULTS: From 1 January 2000 to 15 June 2018, 10 patients (eight females and two males) underwent minimally invasive thoracoscopic IST ablation. Mean age of the patients was 36.7 ± 12.5 years. Mean baseline sinus rate was 113.8 ± 21.8 beats per minute. After surgery, the mean heart rate significantly decreased to 79.8 ± 8.2 at postoperative day 1 and to 75.8 ± 8.1 at day 30 (both P < .001). No in-hospital death, stroke, or PN injury occurred. One patient required reintubation, one patient developed postoperative pericarditis, and another patient had a pulmonary embolus. Median follow-up was 6 months (range, 1-50). Freedom from reintervention was 88% at 6 months. CONCLUSION: Minimally invasive thoracoscopic ablation for IST is a safe and effective approach that preserves the phrenic nerve. Due to the possibility of IST activation site migration, continued follow-up after surgery is required.

Sinus Node Sparing Novel Hybrid Approach for Treatment of Inappropriate Sinus Tachycardia/Postural Orthostatic Sinus Tachycardia With New Electrophysiological Finding.

The ideal treatment of Inappropriate Sinus Tachycardia (IST) and Postural Orthostatic Tachycardia Syndrome (POTS) still needs to be defined. Medical treatment yields suboptimal results, endocardial ablation of the sinus node (SN) may risk phrenic nerve damage and open heart surgery may be accompanied by unjustified invasive risks. We describe our first experience of 50 consecutive patients (41 females, 22.83 ± 3.91 years) having undergone a novel hybrid thoracoscopic ablation for drug resistant IST (n = 39, 78%) or POTS (n = 11, 22%). The SN was identified with the help of 3D mapping. Surgery was performed through 3 (5 mm) ports from the right side. A minimally invasive approach with a radio frequency bipolar clamp was utilized to a new target sparing the SN region, to isolate the superior and the inferior caval veins, and a crista terminalis line was made. All lines were interconnected. Normal SR was restored in all patients at the end of the procedure. All patients discontinued medication during the follow-up. After a blanking period of 6 months all patients presented stable SR. At a mean of 28.4 ± 1.2 months, normal SN ruction and chronotropic response to exercise was present. In the 11 patients initially diagnosed with POTS, no syncope occurred. During the follow-up, pericarditis was the most common complication (39 patients; 78%) with complete resolution in all cases. In conclusions the preliminary results of our first experience with a SN sparing novel hybrid ablation of IST/POTS, using surgical thoracoscopic video-assisted epicardial ablation combined with concomitant endocardial 3D mapping may prove an efficient and safe therapeutic option in patients with symptomatic drug resistant IST and POTS. Importantly, in our study all patients had a complete resolution of the symptoms and restored normal SN activity.

Late Outcomes of Surgical Ablation for Inappropriate Sinus Tachycardia.

BACKGROUND: Inappropriate sinus tachycardia (IST) is a rare clinical disorder characterized by an elevated resting heart rate and an exaggerated rate response to exercise or autonomic stress. Pharmacologic therapy and catheter ablation are considered first-line treatments for IST but can yield suboptimal relief of symptoms. The results of surgical ablation at our center were reviewed for patients with refractory IST. METHODS: Between 1987 and 2018, 18 patients underwent surgical sinoatrial (SA) node isolation for treatment-refractory IST. All 18 patients had previously failed pharmacologic therapy, and 15 patients had failed catheter ablation of the SA node. RESULTS: Ten patients underwent a median sternotomy, and 8 patients underwent a minimally invasive right thoracotomy. The SA node was isolated with the use of surgical incisions, cryoablation, or bipolar radiofrequency ablations. Sinus tachycardia was eliminated in 100% of patients in the immediate postoperative period. Long-term follow-up data were available for 17 patients, with a mean follow-up of 11.4 ± 7.9 years. At last follow-up, 100% of patients were free from recurrent symptomatic IST. More than 80% of patients were completely asymptomatic, whereas 3 patients reported occasional palpitations. Four patients were on ß-blockers, and 5 patients required subsequent pacemaker implantation. All 8 patients who underwent minimally invasive isolation were in normal sinus rhythm at last follow-up, and only 1 patient complained of palpitations. CONCLUSIONS: Surgical isolation of the SA node is a feasible treatment for IST refractory to pharmacologic therapy and catheter ablation. A minimally invasive surgical approach offers a less morbid alternative to traditional median sternotomy.

Three-dimensional mapping and intracardiac echocardiography in the treatment of sinoatrial nodal tachycardias.

Three-dimensional mapping and intracardiac echocardiography are important tools for the study of the site of origin of an arrhythmia and its substrate. This review examines the application of these techniques in the diagnosis and treatment of sinoatrial tachycardias with a special focus on the syndrome of inappropriate sinus tachycardia. The use of these techniques in electrophysiologic mapping and interventions such as catheter ablation is discussed. Three-dimensional mapping provides unique insights into the generation of normal and abnormal sinus impulses in man and their propagation in the atrium. It permits precise placement of ablation lesions and assessment of real-time electrophysiologic impact of these interventions. Intracardiac echocardiography provides delineation of important anatomic structures in the vicinity of the sinoatrial node complex and monitors the safety of interventions such as catheter ablation.

Catheter ablation of inappropriate sinus tachycardia.

Catheter ablation for inappropriate sinus tachycardia (IST) is recommended for patients symptomatic for palpitations and refractory to other treatments. The current approach consists in sinus node modification (SNM), achieved by ablation of the cranial part of the sinus node to eliminate faster sinus rates while trying to preserve chronotropic competence. This approach has a limited efficacy, with a very modest long-term clinical success. To overcome this, proper patient selection is crucial and an epicardial approach should always be considered. This brief review will discuss the current role and limitations of catheter ablation in the management of patients with IST.

Paradoxical embolism interrupted.

A 41 year-old African-American male presented with syncope preceded by shortness of breath at outside facility and transferred to us for management of extensive pulmonary embolism with unstable vital signs. Electrocardiogram showed sinus tachycardia with S1Q3T3 pattern. A transthoracic echocardiogram revealed a freely mobile strand like mass in the left atrium. A transoesophageal echocardiogram showed a very large freely mobile thrombus extending from a patent foramen ovale in to the left atrium. He underwent emergent surgery for the extraction of clot followed by thromboembolectomy from both pulmonary arteries. He made a remarkable recovery and was discharged after seven days of hospital stay.

Epicardial/endocardial sinus node ablation after failed endocardial ablation for the treatment of inappropriate sinus tachycardia.

INTRODUCTION: Success of endocardial sinus node (SN) ablation for refractory inappropriate sinus tachycardia (IST) is limited by the epicardial location of the SN and potential damage to the phrenic nerve (PN). An epicardial approach may overcome these limitations. METHODS AND RESULTS: IST patients who failed endocardial ablation underwent an epicardial approach. Percutaneous pericardial access was obtained with a double wire technique for PN protection (i.e., with a balloon catheter), if needed. Earliest sinus activation was mapped and ablated with remapping for changes in P-wave morphology or sinus rate. The endpoint was total SN ablation (patients with atrial pacing [AP]); otherwise the target was a >25% decrease in sinus rate and inversion of P-wave axis. Five patients (all female, age 36 ± 4 years) underwent ablation. Two had prior AP, and 1 elected to have SN ablation and pacemaker during the same procedure. Three had prior endocardial ablation limited by PN proximity. Baseline sinus rate was 119 ± 20 bpm. After 35.2 ± 21.3 lesions (22.4 ± 21.7 epicardial, 12.8 ± 21.3 endocardial), 4 were in junctional rhythm, 1 in atrial rhythm at 90 bpm. This latter patient had symptom recurrence and underwent combined minimally invasive surgical/catheter SN cryoablation. Atrial tachycardia subsequently occurred and was successfully ablated. The only significant complication was pericarditis (3 patients). At last follow-up (30.4 ± 18.4 months), all had symptom resolution. Two were AP >99%, 1 was AP 54%. Two remain in ectopic atrial rhythm with controlled rates. CONCLUSIONS: Combined epicardial/endocardial SN ablation is a viable approach for patients with severely symptomatic IST after a failed endocardial attempt.

Partial cardiac denervation and sinus node modification for inappropriate sinus tachycardia.

We describe a case of inappropriate sinus tachycardia refractory to medical therapy and catheter sinus node ablation, which was successfully treated by surgery with approaches on both the sinus node and cardiac autonomic ganglia.

Thoracoscopic microwave epicardial ablation: feasibility for the treatment of idiopathic sinus node tachycardia.

Inappropriate sinus tachycardia is a potentially debilitating condition with tachycardia emanating from the sinus node region. Endocardial radiofrequency energy ablation is the current preferred mode of treatment for symptomatic medication failures. Phrenic nerve damage can result from this procedure. We report a case in which the potential for phrenic nerve damage was avoided by using a thoracoscopic approach to displace the phrenic nerve posteriorly and perform epicardial microwave ablation. This resulted in the successful treatment of a patient with highly symptomatic inappropriate sinus tachycardia.

Right diaphragmatic paralysis following endocardial cryothermal ablation of inappropriate sinus tachycardia.

Inappropriate sinus tachycardia (IST) is a rare disorder amenable to catheter ablation when refractory to medical therapy. Radiofrequency (RF) catheter modification/ablation of the sinus node (SN) is the usual approach, although it can be complicated by right phrenic nerve paralysis. We describe a patient with IST, who had symptomatic recurrences despite previous acutely successful RF SN modifications, including the use of electroanatomical mapping/navigation system. We decided to try transvenous cryothermal modification of the SN. We used 2 min applications at -85 degrees C at sites of the earliest atrial activation guided by activation mapping during isoprenaline infusion. Every application was preceded by high output stimulation to reveal phrenic nerve proximity. During the last application, heart rate slowly and persistently fell below 85 bpm despite isoprenaline infusion, but right diaphragmatic paralysis developed. At 6 months follow-up, the patient was asymptomatic and the diaphragmatic paralysis had partially resolved. This is the first report, we believe, of successful SN modification for IST by endocardial cryoablation, although this case also demonstrates the considerable risk of right phrenic nerve paralysis even with this ablation energy.

Isolated anomalous origin of the right pulmonary artery from the ascending aorta (so-called "hemitruncus"): diagnosis and complex management in a newborn.

We report a case of an anomalous origin of the right pulmonary artery (RPA) from the ascending aorta diagnosed at echocardiography at 13 days of age. The diagnostic clue was relieved in the suprasternal and parasternal high short-axis views, showing aorto-RPA continuity with a systolic flow in the left pulmonary artery and a systo-diastolic flow in the RPA. At 34 days of age the infant was submitted to surgery during which a direct end-to-lateral anastomosis without conduit interposition was performed. During the short-term follow-up the patient developed RPA stenosis at the anastomosis site and underwent percutaneous stent implantation.

Radiofrequency catheter ablation of inappropriate sinus tachycardia guided by activation mapping.

OBJECTIVE: The purpose of this study was to evaluate the value of activation mapping for radiofrequency modification of the sinus node and the long-term success rate of the procedure in a series of patients with inappropriate sinus tachycardia. BACKGROUND: The results of radiofrequency ablation of inappropriate sinus tachycardia have been reported in only a small number of patients. METHODS: The subjects of this study were 29 consecutive drug-refractory patients who underwent catheter ablation of inappropriate sinus tachycardia. Target sites were selected by activation mapping during sinus tachycardia. RESULTS: The ablation procedure was successful acutely in reducing the baseline sinus rate to <90/min and the sinus rate during isoproterenol infusion by >20% in 22 of 29 patients (76%). In 13 of 22 patients (59%) with a successful acute outcome, successive applications of radiofrequency energy at the site of earliest endocardial activation resulted in a cranial-caudal migration of earliest endocardial activation from the high lateral right atrium, along with a step-wise reduction in heart rate. In the other nine patients (41%) with a successful acute outcome, the reduction in sinus rate occurred abruptly, unaccompanied by migration of the site of earliest activation. Symptoms due to inappropriate sinus tachycardia recurred at a mean of 4.4+/-; 3 months after the ablation procedure in 6 of 22 patients (27%). After additional procedures in three patients, symptoms of inappropriate sinus tachycardia ultimately were successfully eliminated over the long-term in 19 of 29 patients (66%). CONCLUSIONS: In conclusion, radiofrequency ablation is at best only modestly effective for managing patients with inappropriate sinus tachycardia. The two different responses of heart rate to radiofrequency ablation may reflect differences in the number and/or multicentricity of subsidiary sites of impulse generation within the sinus node and/or atrium in patients with inappropriate sinus tachycardia.

Catheter ablation for patients with atrial tachycardia.

Although atrial tachycardias are relatively rare, their poor response to standard therapies, the suboptimal hemodynamic results of complete atrioventricular node ablation and pacer implantation, and their potential for serious hemodynamic effects make management difficult. Although their mechanisms are complex and divergent, catheter ablation has proven to be highly effective in management of atrial tachycardias. This article discusses arrhythmia mechanisms and therapeutic approaches by catheter ablation.

Surgical treatment of automatic atrial tachycardias.

From 1979 to 1989, 18 patients were seen in the Electrophysiology Service, Duke University Medical Center, with automatic atrial tachycardia. There were 8 male and 10 female patients with a mean age of 28.1 +/- 2.9 years. Electrophysiological mapping localized automatic foci to right atrial sites (14 patients) and left atrial sites (4 patients). Depending on origin of the focus, patients were further diagnosed as having either chronic ectopic atrial tachycardia or inappropriate sinus tachycardia. Of the 15 patients with chronic ectopic atrial tachycardia, 6 responded to medical treatment; in 9, the tachycardia was not adequately controlled. Six of them were referred for surgical intervention. All 3 patients with inappropriate sinus tachycardia underwent operative therapy. In the surgical group of patients with chronic ectopic atrial tachycardia, all 6 had a tachycardia-induced cardiomyopathy with ejection fractions ranging from 14% to 27% (mean ejection fraction, 21% +/- 2.7%). Surgical techniques used (alone or in combination) included an isolation procedure in 1 patient, cryoablation in 4 patients, and excision of atrial appendages or portions of atrial free walls in 7. Normal sinus rhythm developed in all surgical patients except 1 patient who had intractable congestive heart failure preoperatively and died of this condition and stroke. The overall success rates for medical and surgical therapy were 33.3% and 88.9%, respectively (p less than 0.01). Long-term follow-up was possible for 7 (87.5%) of 8 patients 3 to 7 years after operation. All patients with chronic ectopic atrial tachycardia were cured, but only 1 of 3 patients with inappropriate sinus tachycardia was in sinus rhythm.(ABSTRACT TRUNCATED AT 250 WORDS)