Bronchial Injury - Yet Another Collateral Damage of Cryoablation.

With the aging population, the burden of atrial fibrillation is increasing. Cryoablation is a novel technique for pulmonary vein isolation and is considered equally effective as radiofrequency ablation. Some of the known complications of cryoablation include phrenic nerve damage, esophageal injury, pulmonary vein stenosis, new onset atrial flutter, pericardial effusion, and stroke. We present a case of bronchial injury immediately after cryoablation for symptomatic paroxysmal atrial fibrillation. A 67-year-old woman underwent successful pulmonary vein isolation using cryoablation. Her post-operative period was complicated with cough and hemoptysis. During the procedure, she had an extra 3 minutes of freezing of the left inferior pulmonary vein. Her bronchoscopy examination showed blood and erythema in the left main bronchus. She was managed conservatively with cough suppressants and anticoagulation was stopped. Possible etiology of bronchial injury is likely cryoenergy transfer between the pulmonary veins and the bronchus due to their close anatomic proximity. With the increasing use of cryoablation for atrial fibrillation, more cases of bronchial injury will likely be reported in the future. Physicians including electrophysiologist and pulmonologists should be aware of this complication.

A meta-analysis of antibacterial envelope use in prevention of cardiovascular implantable electronic device infection.

OBJECTIVES: Cardiac implantable electronic device (CIED) infection has been a major clinical problem in addition to being a major financial burden. In spite of antimicrobial prophylaxis, CIED infection rates have been increasing disproportionately. We therefore conducted this meta-analysis to assess the role of TYRX antibiotic envelope for the prevention of CIED infection. METHODS: Using extensive online search, we conducted a meta-analysis of studies reporting CIED infections with versus without the use of TYRX antibiotic envelope. A random-effect model was used, and between studies heterogeneity was estimated with I2. All analyses were performed with RevMan (version 5.0.20). RESULTS: Five cohort studies were included in this meta-analysis. The pooled odds ratio (OR) of included studies was 0.29 [95% confidence interval (CI): 0.09-0.94; p < 0.004]. There was evidence of heterogeneity with I2 of 58%. There was also evidence of publication bias on funnel plot analysis. On sensitivity analysis, no statistically significant difference was noted when stratified by study design or duration of follow-up. CONCLUSION: The results of our study demonstrate a significant beneficial effect of TYRX antibiotic envelope for the prevention of CIED infections.

A Stunning Left Atrial Appendage Thrombus.

BACKGROUND: Left atrial appendage thrombus formation is a known major complication of atrial fibrillation and atrial flutter which increases the risk of embolism and stroke. This risk of thrombosis is greatly increased with a lack of anticoagulation. After conversion to a normal sinus rhythm in these arrhythmias, the risk of thrombus formation in the left atrium persists through a phenomenon termed atrial myocardial stunning. CASE: We present the case of a patient who previously underwent successful pulmonary vein isolation and was found to be in typical isthmus-dependent atrial flutter with a questionable recurrence of atrial fibrillation. The decision was made to return for atrial flutter ablation and for evaluation of prior pulmonary vein isolation. Initially, a transesophageal echocardiogram showed a normal ejection fraction, biatrial enlargement and no left atrial appendage thrombus. Ablation of the cavotricuspid isthmus was successfully accomplished with documented bidirectional block. A transesophageal echocardiogram probe was still in place prior to planned transseptal puncture for the evaluation of pulmonary veins. A large thrombus was now observed filling the left atrial appendage. Conclusion and Objective: Atrial stunning is a transient atrial contractile dysfunction that occurs whether sinus rhythm is restored spontaneously, electrically, pharmacologically or by ablation. We know after conversion that there is higher propensity to increased spontaneous echogenic contrast and decreased velocities; however, we do not have documented knowledge of exactly how soon after the conversion to a sinus rhythm a thrombus may be seen. We demonstrate a case of acute left atrial appendage thrombus formation immediately following the successful ablation of isthmus-dependent atrial flutter. Our report validates the belief that strategies of not interrupting anticoagulation prior to the conversion of these arrhythmias should be implemented.

Chocolate Consumption and Risk of Atrial Fibrillation (from the Physicians' Health Study).

Chocolate consumption has been shown to protect against various cardiovascular end points; however, little is known about the association between chocolate consumption and incident atrial fibrillation (AF). Therefore, we prospectively examined the association between chocolate consumption and incident AF in a cohort of 18,819 US male physicians. Chocolate consumption was ascertained from 1999 to 2002 through a self-administered food frequency questionnaire. Incident AF was ascertained through yearly follow-up questionnaires. Cox regression was used to estimate relative risks of AF. The average age at baseline was 66 years (±9.1). During a mean follow-up of 9.0 years (±3.0), 2,092 cases of AF occurred. Using <1 per month of chocolate consumption as the reference group, multivariable adjusted hazard ratios (95% confidence interval) for AF were 1.04 (0.93 to 1.18), 1.10 (0.96 to 1.25), 1.14 (0.99 to 1.31), and 1.05 (0.89 to 1.25) for chocolate intake of 1 to 3 per month and 1, 2 to 4, and ≥5 per week (p for trend 0.25), respectively. In a secondary analysis, there was no evidence of effect modification by adiposity (p interaction = 0.71) or age (p interaction = 0.26). In conclusion, our data did not support an association between chocolate consumption and risk of AF in US male physicians.

Nonobstructive hypertrophic cardiomyopathy with left ventricular aneurysm: the role of cardiac magnetic resonance.

Hypertrophic cardiomyopathy with concomitant left ventricular aneurysm is rare and has important clinical implications, including an increased risk of sudden cardiac death. Most patients with this rare combination have obstructive hypertrophic cardiomyopathy, but we treated a 26-year-old woman who had nonobstructive hypertrophic cardiomyopathy and a family history of probable sudden cardiac death. In our patient, coronary angiograms showed distal occlusion of the left anterior descending coronary artery. Late gadolinium-enhanced cardiac magnetic resonance images showed scattered fibrosis within and beyond the left ventricular aneurysm. Precautionary therapy with an implantable cardioverter-defibrillator yielded an uneventful outcome. Cardiac magnetic resonance has emerged as a promising method for diagnosing these aneurysms and detecting associated myocardial fibrosis, thereby enabling patient risk stratification and the determination of appropriate therapeutic options. We discuss the role of cardiac magnetic resonance imaging in the management of this rare clinical entity.

Idiopathic hypereosinophilic syndrome presenting with cardiac tamponade.

Idiopathic hypereosinophilic syndrome (IHES) is a rare clinical disorder associated with blood and tissue infiltration by eosinophils. Cardiac involvement in patients with IHES can have varied presentations, and is often associated with significant morbidity and mortality. On the other hand, cardiac tamponade is a very rare presentation of IHES, and few anecdotal cases exist in literature. We report on IHES in a patient who presented with cardiac tamponade.

Syncope as an initial manifestation of atypical lipomatous hypertrophy of the interatrial septum.

Lipomatous hypertrophy of the interatrial septum (LHIS) is an incidental echocardiographic abnormality characterized by dumb-bell configuration of the interatrial septum from excess fat deposition. We report a case of syncope in a patient with LHIS obstructing the superior vena cava at the right atrial junction.

Use of octreotide in the treatment of refractory orthostatic intolerance.

There have been reports on the use of octreotide in patients with orthostatic hypotension, postural tachycardia syndrome, and orthostatic syncope. However, there are little if any data on the use of octreotide in patients who have failed multiple other medications. This study was a retrospective chart analysis and was approved by our Institutional Review Board. A total of 12 patients were identified for inclusion in this study. The diagnosis of orthostatic intolerance was based on patient history, physical examination, and response to Head Up Tilt Table testing. These patients had failed multiple medications and were ultimately treated with octreotide. In a retrospective chart review, we collected data, including demographic information, presenting symptoms, laboratory data, tilt-table response, standing heart rate, standing blood pressure before and after treatment (wherever available), and treatment outcomes. Twelve patients aged 33 ± 18 years, eight (66.7%) females, were found to have symptoms of refractory orthostatic intolerance and failed multiple regimens of medication and were ultimately treated with octreotide administration. Five patients (41.7%) had demonstrated a postural tachycardia syndrome pattern, five (41.7%) a neurocardiogenic, and two (16.6%) a dysautonomic response on a Head Up Tilt Table. Symptoms of syncope and orthostatic palpitations improved in six (50%) of the patients. Standing heart rate was significantly reduced after octreotide administration (80 ± 8 versus 108 ± 13; P < 0.05). The standing systolic blood pressure was increased after octreotide administration (107 ± 26 versus 116 ± 22). Three patients (25%) reported complete elimination of syncope, whereas another three had reduction in the frequency of their syncope. However, symptoms of fatigue improved only in two (29%) of the seven patients. Octreotide may improve symptoms in some patients with refractory orthostatic intolerance.

Transmyocardial voyage of a temporary epicardial lead: an unusual long-term complication.

Although the majority of temporary epicardial leads used during cardiac surgery are removed in the perioperative period, occasionally, the wires are cut and allowed to retract into the subcutaneous tissue. Complications arising from such retained epicardial wires are rare. We present a case of transmyocardial migration of a retained epicardial wire through the right ventricular myocardium into the pulmonary artery in a patient who had undergone coronary artery bypass graft surgery 13 years ago. We describe the presentation and successful management of this case.

Erythropoietin in the treatment of postural orthostatic tachycardia syndrome.

Erythropoietin has been reported to improve symptoms of orthostatic intolerance in patients suffering from orthostatic hypotension. Previous reports on the use of erythropoietin in patients with postural orthostatic tachycardia (POTS) have included only a very small number of patients. In the current study, we report on the use of erythropoietin in patients with refractory POTS. The study was approved by the institutional review board. A retrospective nonrandomized analysis was performed on 39 patients evaluated at our autonomic center for POTS from 2003 to 2010. The diagnosis of POTS was based on patient history, physical examination, and response to head-up tilt-table testing. The mean follow-up period was 6 months. The patients were included in the current study if they had a diagnosis of POTS with severe symptoms of orthostatic intolerance and were refractory to the commonly used medications. All these patients were started on erythropoietin, and the response to therapy was considered successful if it provided symptomatic relief. We screened 200 patients with POTS and found 39 patients (age 33 ± 12, 37 females) to be eligible for inclusion in the current study. The response to the treatment was assessed subjectively in each patient and was obtained in a retrospective fashion from patient charts and physician communications. Eight (21%) patients demonstrated no improvement in symptoms after administration of erythropoietin. Three (8%) patients showed an improvement in symptoms of orthostatic intolerance of <3 months. Twenty-seven (71%) patients demonstrated sustained improvement in their symptoms of orthostatic intolerance at the mean follow-up of 6 months. Erythropoietin significantly improved sitting diastolic blood pressure but had no effect on other hemodynamic parameters. In a select group of POTS patients who are refractory to commonly used medications, erythropoietin may help improve symptoms of orthostatic intolerance.

Use of methylphenidate in the treatment of patients suffering from refractory postural tachycardia syndrome.

Methylphenidate has been shown to be an effective therapy in patients with refractory neurocardiogenic syncope. However, the role of methylphenidate in patients suffering from postural orthostatic tachycardia (POTS) has not been reported. The study was approved by the institutional review board. A retrospective nonrandomized analysis was preformed on 24 patients evaluated at our autonomic center for POTS from 2003 to 2010. The diagnosis of POTS was based on patient history, physical examination, and response to head up tilt table testing. The mean follow-up period was 9 ± 3 months. The patients were included in the current study if they had a diagnosis of POTS with severe symptoms of orthostatic intolerance and were refractory to the commonly used medications. All of these patients were started on methylphenidate and the response to therapy was considered successful if it provided symptomatic relief. Twenty-four patients (age 28 ± 12, 20 women) met inclusion criterion for this study. The response to treatment was assed subjectively in each patient and was collected in a retrospective fashion from patient charts and physician communications. Four patients reported side effects in the form of nausea and 2 ultimately had to discontinue the treatment. Another 4 patients had a follow-up of less than 6 months. Thus, only 18 patients who received methylphenidate completed the follow-up of 6 months. Out of these 18 patients, 14 (77%) patients reported marked improvement in their symptoms. Nine out of 12 patients who had recurrent episodes of syncope reported no syncope at 6 months of follow-up. Fourteen (77%) patients reported marked improvement in their symptoms of fatigue and presyncope. Four patients continue to have symptoms of orthostatic intolerance and 3 continued to have recurrent episodes of syncope. Methylphenidate may be beneficial in patients with otherwise refractory postural tachycardia syndrome.

Clinical presentation and management of patients with hyperadrenergic postural orthostatic tachycardia syndrome. A single center experience.

BACKGROUND: We present our single center experience of 27 patients of hyperadrenergic postural orthostatic tachycardia syndrome (POTS). METHODS: In a retrospective analysis, we reviewed the charts of 300 POTS patients being followed at our autonomic center from 2003 to 2010, and found 27 patients eligible for inclusion in this study. POTS was defined as symptoms of orthostatic intolerance (of greater than six months' duration) accompanied by a heart rate increase of at least 30 bpm (or a rate that exceeds 120 bpm) that occurs in the first 10 min of upright posture or head up tilt test (HUTT) occurring in the absence of other chronic debilitating disorders. Patients were diagnosed as having the hyperadrenergic form based on an increase in their systolic blood pressure of ≥ 10 mm Hg during the HUTT (2) with concomitant tachycardia or their serum catecholamine levels (serum norepinephnrine level ≥ 600 pg/mL) upon standing. RESULTS: Twenty seven patients, aged 39 ± 11 years, 24, (89%) of them female and 22 (82%) Caucasian were included in this study. Most of these patients were refractory to most of the first and second line treatments, and all were on multiple combinations of medications. CONCLUSIONS: Hyperadrenergic POTS should be identified and differentiated from neuropathic POTS. These patients are usually difficult to treat and there are no standardized treatment protocols known at this time for patients with hyperadrenergic POTS.

Pyridostigmine in the treatment of postural orthostatic tachycardia: a single-center experience.

BACKGROUND: The long-term efficacy of pyridostigmine, a reversible acetyl cholinesterase inhibitor, in the treatment of postural orthostatic tachycardia syndrome (POTS) patients remains unclear. We report our retrospective, single-center, long-term experience regarding the efficacy and adverse effect profile of pyridostigmine in the treatment of POTS patients. METHODS: This retrospective study included an extensive review of electronic charts and data collection in regards to patient demographics, orthostatic parameters, side-effect profile, subjective response to therapy, as well as laboratory studies recorded at each follow-up visit to our institution's Syncope and Autonomic Disorders Center. The response to pyridostigmine therapy was considered successful if patient had both symptom relief in addition to an objective response in orthostatic hemodynamic parameters (heart rate [HR] and blood pressure). Three hundred patients with POTS were screened for evaluation in this study. Of these 300, 203 patients with POTS who received pyridostigmine therapy were reviewed. Of these 203 patients, 168 were able to tolerate the medication after careful dose titration. The mean follow-up duration in this group of patients was 12 ± 3 (9-15) months. Pyridostigmine improved symptoms of orthostatic intolerance in 88 of 203 (43%) of total patients or 88 of 172 (51%) who were able to tolerate the drug. The symptoms that improved the most included fatigue (55%), palpitations (60%), presyncope (60%), and syncope (48%). Symptom reduction correlated with a statistically significant improvement in upright HR and diastolic blood pressure after treatment with pyridostigmine as compared to their baseline hemodynamic parameters (standing HR 94 ± 19 vs 82 ± 16, P < 0.003, standing diastolic blood pressure 71 ± 11 vs 74 ± 12, P < 0.02). Gastrointestinal problems were the most common adverse effects (n = 39, 19%) reported. The overall efficacy of pyridostigmine in our study was seen in 42% of total patients or 52% of patients who could tolerate taking the drug. CONCLUSION: The subgroup of POTS patients who can tolerate oral pyridostigmine may demonstrate improvement in their standing HR, standing diastolic blood pressure, and clinical symptoms of orthostatic intolerance.

Postural orthostatic tachycardia syndrome following Lyme disease.

BACKGROUND: A subgroup of patients suffering from Lyme disease (LD) may initially respond to antibiotics only to later develop a syndrome of fatigue, joint pain and cognitive dysfunction referred to as 'post treatment LD syndrome'. We report on a series of patients who developed autonomic dysfunction in the form of postural orthostatic tachycardia syndrome (POTS). METHODS: All of the patients in this report had suffered from LD in the past and were successfully treated with antibiotics. All patients were apparently well, until years later when they presented with fatigue, cognitive dysfunction and orthostatic intolerance. These patients were diagnosed with POTS on the basis of clinical features and results of the tilt table (HUTT) testing. RESULTS: Five patients (all women), aged 22-44 years, were identified for inclusion in this study. These patients developed symptoms of fatigue, cognitive dysfunction, orthostatic palpitations and either near syncope or frank syncope. The debilitating nature of these symptoms had resulted in lost of the employment or inability to attend school. Three patients were also suffering from migraine, two from anxiety and depression and one from hypertension. All patients demonstrated a good response to the employed treatment. Four of the five were able to engage in their activities of daily living and either resumed employment or returned to school. CONCLUSIONS: In an appropriate clinical setting, evaluation for POTS in patients suffering from post LD syndrome may lead to early recognition and treatment, with subsequent improvement in symptoms of orthostatic intolerance.

Neurocardiogenic syncope coexisting with postural orthostatic tachycardia syndrome in patients suffering from orthostatic intolerance: a combined form of autonomic dysfunction.

INTRODUCTION: There is anecdotal evidence that one or more forms of orthostatic intolerance (OI) subgroups may coexist in the same patients. However, there is a paucity of published data on the clinical features and management of patients who suffer from coexisting features of postural tachycardia syndrome (POTS) and neurocardiogenic syncope (NCS). We herein present our experience of 18 patients who we found displayed evidence of coexisting NCS and POTS. METHODS: We reviewed charts of 300 POTS patients seen at the University of Toledo Syncope and Autonomic Disorders Center from 2003 to 2010 and found 18 patients eligible for inclusion in this study. Patients were included in this study if they reported clinical symptoms consistent with both POTS and NCS and then demonstrated a typical POTS pattern (a rise in heart rate without change in blood pressure [BP]) on head up tilt table (HUTT) within the first 10 minutes of upright posture followed by a neurocardiogenic pattern (a sudden fall in heart rate and/or fall in blood pressure) reproducing symptoms that were similar to the patients spontaneous episodes. RESULTS: We found 18 patients, mean age (30 ± 12), with 15 (84%) women and three (16%) men, who met the inclusion criterion for this study. Each of these 18 patients demonstrated a typical POTS pattern within the first 10 minutes on initial physical exam and on a HUTT. Continued tilting beyond 10 minutes resulted in a sudden decline in heart rate (which in some patients manifested as an asystole that lasted anywhere between 10 and 32 seconds [mean of 18 seconds]) and/or a fall in BP in each of these patients demonstrating a pattern consistent with neurocardiogenic subtype of OI. The mean time to the NCS pattern of a fall in BP and heart was 15 minutes with a range of 13-20 minutes. This group of patients was highly symptomatic and reported frequent clinical symptoms that were suggestive of OI. Recurrent presyncope, syncope, orthostatic palpitations, exercise intolerance, and fatigue were the principal symptoms reported. CONCLUSION: NCS may coexist with POTS in a subgroup of patients suffering from OI.

Preliminary observations suggesting that treatment with modafinil improves fatigue in patients with orthostatic intolerance.

Many patients who suffer from orthostatic intolerance (OI) may also have severe fatigue and extreme exercise intolerance. In some of these patients, fatigue may be so severe that they are unable to maintain employment. In some, even the activities of the daily living may be compromised. We report on the use of modafinil in a subgroup of patients who failed therapy with commonly used medication for fatigue in patients with OI. The study was approved by the institutional review board. A retrospective nonrandomized analysis was preformed on 60 patients evaluated at our autonomic center for OI from 2003 to 2010. The diagnosis of OI was based on patient history, physical examination, and reponse to head up tilt table testing. All these patients had fatigue as their predominant symptom. Multiple trials of stimulants including methylphenidate, amphetamine, or dextroamphetamine failed to provide symptomatic relief of fatigue in these patients. Each patient received modafinil (100-200 mg daily). The mean follow-up period was 9 ± 3 months. A treatment was considered successful if it provided symptomatic relief from fatigue for the patient. Sixty patients, age 29 ± 15, 52 women were included in the analysis. Migraine (57%) and joint hypermobility syndrome (33%) were common comorbidities. Out of 60 patients, 40 patients reported initial improvement with initiation of modafinil therapy. Twenty patients reported no change in their symptoms of fatigue. Of the 40 patients who showed initial improvement in their symptoms 4 had eventual recurrence of fatigue after 3 months of modafinil therapy. Thirty-six patients continued to demonstrate symptom relief from fatigue for more than 6 months. In a selective group of patients of OI, modafinil may improve fatigue.

McConnell Sign in a Patient with Massive Acute Pulmonary Embolism.

A 48-year-old female was admitted after experiencing a brief syncopal episode. Three weeks ago the patient sustained a right arm humerus bone fracture in a motor vehicle accident. Since the accident, her mobility has been limited. CT angiogram of the chest revealed massive bilateral pulmonary emboli. A 2D echocardiogram was performed, which demonstrated McConnell sign and severe right ventricle dysfunction. Considering potential of hemodynamic instability, the patient received fibrinolytic therapy with Alteplase. A subsequent 2D echocardiogram showed complete resolution of McConnell sign and right ventricle dysfunction.

Autonomic dysfunction presenting as orthostatic intolerance in patients suffering from mitochondrial cytopathy.

BACKGROUND: Disturbances in autonomic nervous system function have been reported to occur in patients suffering from mitochondrial cytopathies. However, there is paucity of literature on the occurrence of orthostatic intolerance (OI) in these patients. We report on a series of patients diagnosed with mitochondrial cytopathy who developed features of autonomic dysfunction in the form of OI. METHODS: This was a single-center report on a series of 6 patients who were followed in our clinic for orthostatic intolerance. All of these patients had a diagnosis of mitochondrial cytopathy on the basis of muscle biopsy and were being followed at a center specializing in the treatment of mitochondrial disorders. This study was approved by our local institutional review board. Each of the patients had suffered from symptoms of fatigue, palpitations, near syncope, and syncope. The diagnosis of OI was confirmed by head-up tilt test. Collected data included demographic information, presenting symptoms, laboratory data, tilt-table response, and treatment outcomes. RESULTS: Six patients (3 females) were identified for inclusion in this report. The mean age of the group was 48 ± 8 years (range, 40-60 years). All of these patients underwent head-up tilt table testing and all had a positive response that reproduced their clinical symptoms. Among those having an abnormal tilt-table pattern, 1 had a neurocardiogenic response, 1 had a dysautonomic response, and 4 had a postural orthostatic tachycardia response. All but 1 patient reported marked symptom relief with pharmacotherapy. The patient who failed pharmacotherapy received a dual-chamber closed-loop pacemaker and subsequently reported marked improvement in her symptoms with elimination of her syncope. CONCLUSIONS: Orthostatic intolerance might be a significant feature of autonomic nervous system dysfunction in patients suffering from mitochondrial cytopathy.

Autonomic dysfunction presenting as postural tachycardia syndrome following traumatic brain injury.

BACKGROUND: Autonomic dysregulation (also called diencephalic epilepsy) has been reported following traumatic brain injuries (TBI). However, until now, postural tachycardia syndrome (POTS) has not been reported as a long-term complication in patients who have suffered a TBI. We report on a series of patients who developed POTS after suffering TBI. METHODS: Eight patients who were referred to our center had suffered TBI and developed features of orthostatic intolerance following head trauma. The patients' neurological, neurosurgical and autonomic data (charts and/or physician letters) were then carefully reviewed for demographic characteristics, comorbid conditions, symptoms of orthostatic intolerance, medications and response to medication. These patients were diagnosed as having POTS, primarily based on their clinical features and findings from the head-up tilt test (HUTT). The data presented is observational and descriptive (percentages or means). RESULTS: Eight patients (seven of them women) aged 21-41 years had suffered from TBI and had developed features of POTS. All had been normal with no symptoms prior to their TBI. All patients experienced orthostatic dizziness, fatigue, palpitations and near syncope. Six patients suffered from frank syncope. Six patients developed significant cognitive dysfunction, and three developed a chronic pain syndrome following trauma. All of the patients reported severe limitations to their daily activities and had been unable to keep their jobs, and two were housebound. Six patients demonstrated a good response to therapy with various combinations of medication. The symptoms of orthostatic intolerance and syncope improved with the initiation of medical therapy, as well as their reported quality of life. Two patients failed to show any improvement with various combinations of medications and tilt training, and continued to experience orthostatic difficulties. CONCLUSIONS: Postural tachycardia syndrome may, in some cases, be a late complication of traumatic brain injury.

New onset postural orthostatic tachycardia syndrome following ablation of AV node reentrant tachycardia.

BACKGROUND: Autonomic dysfunction presenting as inappropriate sinus tachycardia has been reported to occur following slow pathway ablation for atrioventricular node tachycardia. We report on a series of patients who developed new onset postural orthostatic tachycardia syndrome (POTS) following successful radiofrequency ablation of atrioventricular nodal reentrant tachycardia (AVNRT). METHODS: The study was a retrospective analysis that was approved by our Institutional Review Board. Patients were identified from those seen at our Syncope and Autonomic Disorders Clinic. A total of six patients were identified who were previously healthy except for supraventricular tachycardia. Each was found to have AVNRT during electrophysiology study and each underwent successful radiofrequency modification of the slow atrioventricular nodal pathway. Following ablation each patient developed the new onset of symptoms of orthostatic intolerance consistent with POTS. RESULTS: After an initial symptom-free period (3-6 weeks) post ablation each patient began to experience symptoms of orthostatic intolerance. All six patients began to experience progressive severe fatigue. Orthostatic tachycardia was reported by five patients, syncope by three patients, and presyncope by all six patients. Each patient reported the occurrence of symptom while upright that were relieved by becoming supine. Each patient had experienced symptoms for greater than 6 months prior to being seen at our center. Three patients reported such severe symptoms of orthostatic tachycardia that they underwent repeat electrophysiology study; however, none had evidence of AVNRT. Each patient demonstrated a POTS response within the first 10 min of upright tilt with reproduction of their clinical symptoms that had occurred post ablation. CONCLUSION: POTS may be a complication of radiofrequency ablation of AVNRT.