Intracardiac echocardiography guided anatomical ablation of the arcuate ridge for drug refractory inappropriate sinus tachycardia.

INTRODUCTION: Inappropriate sinus tachycardia (IST) is a common condition with frequently not tolerated beta-blockers or ivabradine and a high rate of complication in ablation strategy; we describe an alternative anatomical approach of sinus node (SN) modulation. METHODS: This retrospective study describes a case series of 6 patients from two centers diagnosed with symptomatic IST undergoing SN ablation. RESULTS: The mean age was 40.6 ± 13.9 years; five of the six patients were female, 100% of patients reported heart palpitations, and 66% reported dizziness, the average heart rate (HR) on a 24-h Holter was 93.2 ± 7.9 bpm. HR during the first stage of a stress test using a standard Bruce protocol was 150 ± 70 bpm, The average HR on 24-h Holter postablation was 75 ± 5.6 bpm, the sinus rate HR during stage 1 of a Bruce protocol exercise stress test was 120 ± 10 bpm. CONCLUSION: This is the first case series reporting the acute and long-term results of a novel anatomical approach for SN modulation to treat IST targeting the arcuate ridge (AR) under intracardiac echography (ICE) guidance. The novel anatomic ICE-guided catheter ablation approach aimed to identify the earliest activation at the AR with an extension of RF lesions toward its septal region seems effective and safe to modulate the SN in symptomatic patients with IST refractory to medical treatment.

Redo procedures after sinus node sparing hybrid ablation for inappropriate sinus tachycardia/postural orthostatic sinus tachycardia.

AIMS: A novel sinus node (SN) sparing hybrid ablation for inappropriate sinus node tachycardia (IST)/postural orthostatic tachycardia syndrome (POTS) has been demonstrated to be an effective and safe therapeutic option in patients with symptomatic drug-resistant IST/POTS. The aim of this study was to evaluate the long-term rate of redo procedures after hybrid IST ablation and procedural strategy, outcomes and safety of redo procedures. METHODS AND RESULTS: All consecutive patients from 2015 to 2023 were prospectively enrolled in the UZ Brussel monocentric IST/POTS registry. They were analysed if the following inclusion criteria were fulfilled: 1) diagnosis of IST or POTS, 2) symptomatic IST/POTS refractory or intolerant to drugs, and 3) hybrid SN sparing ablation performed. The primary endpoint was redo procedure. The primary safety endpoint was pacemaker (PM) implantation. A total of 220 patients undergone to hybrid IST ablation were included, 185 patients (84.1%) were treated for IST and 61 patients (27.7%) for POTS.After a follow-up of 73.3 ± 16.2 months, 34 patients (15.4%) underwent a redo. A total of 23 patients (67.6%) had a redo for IST recurrence and 11 patients (32.4%) for other arrhythmias. Pacemaker implantation was performed in 21 patients (9.5%). Nine patients (4.1%) had no redo procedure and experienced sick sinus syndrome requiring a PM. Twelve patients (5.4%) received a PM as a shared therapeutic choice combined with SN ablation procedure. CONCLUSION: In a large cohort of patients the long-term free survival from redo procedure after hybrid IST ablation was 84.6% with a low PM implantation rate.

Efficacy of medical and ablation therapy for inappropriate sinus tachycardia: A single-center experience.

BACKGROUND: Effective therapy for inappropriate sinus tachycardia (IST) remains challenging with high rates of treatment failure and symptom recurrence. It is uncertain how effective pharmacotherapy and procedural therapy are long-term, with poor response to medical therapy in general. METHODS: We retrospectively reviewed all patients with the diagnosis of IST at a tertiary academic medical center from 1998 to 2018. We extracted data related to prescribing patterns and symptom response to medical therapy and sinus node modification (SNM), assessing efficacy and periprocedural complication rates. RESULTS: A total of 305 patients with a formal diagnosis of IST were identified, with 259 (84.9%) receiving at least one prescription medication related to the condition. Beta-blockers were the most commonly used medication (n = 245), with a majority of patients reporting no change or worsening of symptoms, and poor response was seen to other medication classes. Improvement was seen significantly more often with ivabradine than beta blockers, though the sample size was limited (p = .003). Fifty-five patients (18.0% of all IST patients), mean age 32.0 ± 9.1 years, underwent a SNM procedure, with an average of 1.8 ± 0.9 procedures per patient. Acute symptomatic improvement (<6 months) was seen in 58.2% of patients. Long-term complete resolution of symptoms was seen in 5.5% of patients, modest improvement in 29.1%, and no long-term benefit was seen in 65.5% of patients. CONCLUSIONS: Among all medical therapies, there were high rates of treatment failure or symptom worsening in over three-quarters of patients in our study. Ivabradine was most beneficial, though the sample size was small. While most patients receiving SNM ablation for IST perceive an acute symptomatic improvement, almost two-thirds of patients have no long-term improvement, and resolution of symptoms is quite rare. AV node ablation with pacemaker implantation following lack of response to SNM offered increased success, though the sample size was limited.

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.

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.

Symptomatic sinus tachycardia with perpetuating slow pathway: successful treatment with radiofrequency ablation.

We report a case of sinus tachycardia with perpetuating slow pathway (SP) conduction in a 42-year-old woman who developed severe symptoms as a result of atrioventricular (AV) desynchronization. The restoration of an AV synchrony, achieved with selective radiofrequency ablation of the SP, eliminated the symptomatic arrhythmia and may represent a reasonable therapeutic option despite the fact that the patient has no AV-node reentrant tachycardia. This case demonstrates the importance of AV timing.

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.

Frequent additional tachyarrhythmias in patients with inappropriate sinus tachycardia undergoing sinus node modification: an important cause of symptom recurrence.

BACKGROUND: Symptom recurrence following sinus node modification (SNM) for inappropriate sinus tachycardia (IST) remains significant despite achieving acute procedural success. The impact of non-IST tachyarrhythmias on symptom recurrence remains poorly characterized. OBJECTIVES: The objective was to determine the prevalence and nature of additional tachyarrhythmias preceding and following SNM for IST. METHODS: Consecutive patients with IST undergoing SNM at the University of Pennsylvania were studied. SNM was initially performed using an anatomic approach targeting the superolateral crista terminalis under intracardiac echocardiographic guidance and later using an electrophysiologic approach, targeting the site of the earliest right atrial activation during maximum heart rate (HR) with isoproterenol infusion. An effort was made to shift the site more caudally until a decrease of >25% in resting HR was achieved, with a blunted response to isoproterenol and flattening of the P-wave axis in leads III and aVF. Patients were followed for arrhythmia recurrence. Tachyarrhythmias were documented with electrocardiographic monitoring and then characterized during EP study. RESULTS: Thirty-three patients underwent SNM and were followed for a mean of 2.0 ± 1.5 years. During follow-up, 27% developed a non-IST tachyarrhythmia and 18% developed recurrent IST. Additionally, 42% of patients had a non-IST tachyarrhythmia prior to SNM. CONCLUSIONS: Non-IST tachyarrhythmias are common in patients with IST before and after SNM. A major reason for symptom recurrence following SNM is development of a non-IST tachyarrhythmia. These tachyarrhythmias should be detected and treated to optimize patient outcomes.

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.

First experience of monitoring with cardiac event recorder electrocardiography Omron system in childhood population for sporadic, potentially arrhythmia-related symptoms.

AIMS: To document symptomatic episodes of palpitations with traditional methods such as24 h Holter monitoring (HM) or loop recorders remains a big challenge in clinical practice. Clinical trials with patient-activated electrocardiography (ECG) recorders show increased diagnostic yield in such patients. However, studies in the paediatric population are limited. We want to present a first experience with an event-recording system Omron HeartScan in children with symptomatic palpitations. METHODS AND RESULTS: Thirty paediatric patients (age 4-16 years) were followed with the Omron at our centre. All patients had a normal echocardiogram, a normal baseline 12-lead ECG and a normal 24 h HM. Indications with regard to monitoring were palpitations (n = 30). Two of them also had episodes of pre-syncope. The average of palpitation episodes in the past 3 months was 13.2 ± 8.3. The mean age of the study population was 9.7 ± 2.3 years [17 males (56.7 %)]. In all patients (n = 30) a diagnostic event could be recorded with the studied system. Four patients were diagnosed with supraventricular tachycardia (SVT) and underwent catheter ablation. The remaining patients (n = 26; 87%) were diagnosed with sinus tachycardia. Two patients with SVT additionally had episodes of pre-syncope. None of the patients could be diagnosed with previous 24 h HM. CONCLUSION: This event recorder has a high diagnostic yield in the childhood population. The children enjoyed the ease of using the system under daily-life conditions. In this study the system was able to record a diagnostic event in all patients with palpitations.

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.

Long-term outcomes of sinus node modification in patients with severely symptomatic drug-refractory inappropriate sinus tachycardia: a single-center experience.

BACKGROUND: The purpose of the study was to evaluate the long-term outcomes of sinus node modification (SNM) in treating patients with severely symptomatic drug-refractory inappropriate sinus tachycardia (IST). METHODS: The study included 39 patients with symptomatic drug-refractory IST who have undergone SNM at Saint Louis University Hospital. Data was reviewed retrospectively. Recurrence of symptoms was assessed at 3-6-month follow-up intervals. RESULTS: The mean age of our cohort was 31.5 ± 11. The mean HR at diagnosis was 135 ± 25.4 beats per minute (BPM). Thirty-seven of 39 (94.8%) patients had complete resolution of symptoms. Of these 37 patients, 16 required 1 SNM, 17 patients required 2 SNM, and 4 patients required 3 SNM in order to achieve complete symptom resolution. Mean HR post-procedure was 78.6 ± 12.3 BPM. Thirteen of 39 patients required rate control medication post-procedure, all of whom were prescribed beta-blockers. Patients were followed every 3 to 6 months with a mean follow-up duration of 62.3 ± 42.9 months from the patient's last SNM procedure. Thirteen of those 37 patients (35.1%) developed intermittent symptomatic bradycardia requiring permanent pacemaker implantation. Two of the 39 patients had phrenic nerve injury, and 6 patients had post-procedure pericarditis. CONCLUSIONS: This study provides additional information to the limited dataset available in the literature and shows that SNM might provide patients with long-term symptomatic relief bearing in mind the potential increased risk for the need for permanent pacing.

Post-COVID-19 Tachycardia Syndrome: A Distinct Phenotype of Post-Acute COVID-19 Syndrome.

In this paper we highlight the presence of tachycardia in post-acute COVID-19 syndrome by introducing a new label for this phenomenon-post-COVID-19 tachycardia syndrome-and argue that this constitutes a phenotype or sub-syndrome in post-acute COVID-19 syndrome. We also discuss epidemiology, putative mechanisms, treatment options, and future research directions in this novel clinical syndrome.

[Inappropriate sinus tachycardia - non-contact mapping and ablation]. / Nieadekwatna tachykardia zatokowa - ablacja z zastosowaniem mapowania przestrzennego bezkontaktowego EnSite Array.

Two cases of inappropriate sinus tachycardia refractory to combined pharmacotherapy (beta-blocker, ivabradine) are described. Both were female patients (28 and 45 years-old) and underwent sinus node modification/ablation using non-contact mapping (EnSite Array). Since ablation had to be performed in both cases very close to the phrenic nerve (captured during 10V pacing at ablation spots) its function was monitored during ablation with constant phrenic nerve pacing from the superior vena cava. One case was successful after single and straightforward ablation session, the other case despite several attempts and initially good result had recurrences; first recurrence two days after cryoablation, and second three weeks after radiofrequency ablation with irrigated tip catheter.

Migration of the breakthrough: the advantage of noncontact mapping in targeting inappropriate sinus tachycardia.

We report on a 42-year-old female patient with inappropriate sinus tachycardia (IST), in whom an effective sinus node modification was made by using the noncontact mapping system. The patient was admitted with palpitations and a heart rate between 90-110 beats per minute (bpm). Her heart rate increased to 150 bpm during minimal exercise. After confirming the diagnosis of IST by an electrophysiological study, radiofrequency catheter ablation was performed. A color-coded isopotential map was created when the heart rate was 95 bpm and the initial breakthrough of the sinus node (SNB) was labeled. After administration of isoproterenol, a new color-coded map recording was created when the heart rate reached 160 bpm, showing a new breakthrough 24 mm away from the SNB. Radiofrequency was delivered to this region and the heart rate decreased to 120 bpm. After another infusion of isoproterenol, the maximum heart rate reached 140 bpm and another isopotential map recording was created, which demonstrated migration of the breakthrough 16 mm away from the SNB. Radiofrequency was delivered to the second site and the heart rate decreased to 90 bpm and increased to a maximum of 120 bpm after a new isoproterenol infusion. A subsequent infusion caused no increase in the heart rate, and the ablation procedure was terminated. During a follow-up of one year, the patient was in sinus rhythm with a mean heart rate of 80 bpm.

A novel method for sinus node modification and phrenic nerve protection in resistant cases.

This is a case report of inappropriate sinus tachycardia in a patient who had a previous unsuccessful endocardial ablation, which had been limited due to concerns of phrenic nerve injury. The patient required a repeat ablation that utilized a novel combined epicardial and endocardial approach for sinus node modification and simultaneous protection of the phrenic nerve via an epicardial balloon.

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.

[Inadequate, inappropriate sinus-node tachycardia. An old cardiac arrhythmia in a new perspective]. / Inadekvát, aránytalan sinuscsomó-tachycardia. Egy régi szívritmuszavar új megvilágításban.

Introduction: The inadequate, inappropriate sinus-node tachycardia is not a rare clinical syndrome, defined as a non-paroxysmal, increased sinus-rate at rest, and/or inadequate response to physical and/or emotional stress, and palpitations. Aim: The aim of this study was to describe our experiences with the investigations of our inappropriate sinus-node tachycardia patients. Method: In the last years, 104 patients (92 women, 12 men, mean age: 31 ± 10 years) were treated with this cardiac arrhythmia entity. All patients underwent 12 leads ECG, chest X-ray, echocardiography, Holter-monitoring and transtelephonic ECG observations. The quality of life score was estimated by using the European Heart Rhythm Association scale. Results: Patients had no structural heart disease (physical examination ECG, chest X-ray, echocardiography were normal), the laboratory values (TSH, blood count) were within normal limits, but the resting heart rates were repeatedly high (102 ± 8/min). The results of Holter recording (expressed as minimal-maximal [average] heart rate/min) without drug therapy showed high heart rate values (59 ± 8, 160 ± 14 [94 ± 6]/min). The standard bicycle ergometry showed an average loading capacity of 124 ± 23 watt (heart rate: control: 99 ± 12/min, top: 167 ± 13/min) with early, inadequate sinus tachycardia. To disclose the episodes of paroxysmal supraventricular tachycardia, beside the Holter-monitoring transtelephonic ECG system was used. This diagnostic modality was very useful for the exclusion of paroxysmal supraventricular tachycardia episodes during the palpitation symptoms. Out of 104 patients, 4 patients (3.8%) showed familiar occurrence, another 16 patients (15.2%) had previous slow-pathway radiofrequency ablation due to atrioventricular nodal reentry tachycardia. Conclusions: Based on our clinical observations, it can be pointed out that inappropriate sinus-node tachycardia syndrome (1) occurs mainly in young women, mostly in students, inducing decreased quality of life scores (EHRA score: 2.3 ± 0.4); (2) the prevalence in our outpatient clinic was 0.7%; (3) the patient population is not homogeneous: familiar or postablation occurrence is possible in some patients; (4) transtelephonic ECG has been proved to be very useful to disclose episodes of paroxysmal supraventricular tachycardia in these patients. Orv Hetil. 2019; 160(37): 1464-1470.