Sinus Dysrhythmia in Kearns-Sayre Syndrome

Kearns-Sayre syndrome is the triad of progressive external ophthalmoplegia, pigmentary retinopathy, and complete AV block. The etiology is unknown, but is thought to be due to a mitochondrial DNA deletion. Reported electrocardiographic abnormalities include first-degree AV block, fascicular blocks, and complete heart block, as well as nonspecific S-T segment changes and T wave abnormalities, but has not included sinus node dysfunction. We report a case with episodes of sinus arrest in an asymptomatic patient with Kearns-Sayre syndrome resulting in pauses lasting up to 6 seconds.     

Effects of ramipril on the neurohormonal response to exercise in patients with mild or moderate congestive heart failure

Static measurements of plasma neurohormones at rest may notbe adequate to detect alterations in cardiovascular controlmechanisms in congestive heart failure (CHF). Therefore, itis of interest to study neurohormonal activation during differentphysiological conditions. Plasnw neurohormones were measuredin 54 patients on diuretic therapy for mild or moderate CHF.Samples were taken at rest and immediately after maximal bicycleexercise, before and after 12 weeks of treatment with ramiprilor placebo. There was a strong correlation between the plasmalevels of each hormone before and after exercise. An inversecorrelation existed at baseline between exercise duration andangiotensin II levels after maximal exercise (r= – 0·30,P=0·03), but not at rest. Plasma levels of angiotensinII, aldosterone, atrial natriuretic peptide (ANP) and noradrenalinewere increased after maximal exercise compared to rest. Plasmaangiotensin converting enzyme activity and ANP were reducedby ramipril compared to placebo, both at rest and after exercise,but levels of angiotensin II, aldosterone and nordrenaline werenot significantly affected Thus, exercise consistently activatesneurohormonal systems in patients with CHF. Patients with thelowest exercise duration had the highest angiotensin II levelsafter exercise. Measurements of plasma neurohormones after maximalexercise provide limited additional value to measurements atrest.     

Mechanisms of Recovery From Neutropenia Induced by Hemodialysis

Profound, transient neutropenia is observed early in hemodialysis. The presentstudies were performed during 11 twin-coil dialyses in eight patients withchronic renal failure to determine if therapid recovery reflects remobilization ofsequestered neutrophils and/or if marrow reserves are utilized. In five studies,in vitro cell tagging with diisopropylfluorophosphate-³²P (DF ³²P) and reinfusion were performed 4-6 hr beforeroutine hemodialysis. In all 11 studies amarked decrease of the absolute neutrophil count occurred within 15 min ofstarting blood return from the coil. Innine studies carried on over a sufficientperiod of time, a rebound of the neutrophil count to levels significantly higherthan the highest control counts occurredby 1-3 hr after starting dialysis. Inthe radioactive studies during the rebound phase, most or all of the expectednumber of labeled neutrophils returnedto the circulation, but simultaneously inall cases a large number of extra unlabeled neutrophils appeared in circulation. Since there are two sources foradditional circulating neutrophils—themarginated pool and the marrow reserves—and since the marginated poolunder the study conditions would beexpected to have the same specific radioactivity as the circulating pool, the dataare consistent with the hypothesis thatthere was an immediate marrow responseto neutropenia.

Submitted on March 24, 1971 Revised on May 25, 1971 Accepted on May 27, 1971     

Aborted Sudden Cardiac Death Due to Radiofrequency Ablation Within the Coronary Sinus and Subsequent Total Occlusion of the Circumflex Artery

We report a case of aborted sudden cardiac death and subsequent development of malignant drug‐refractory incessant ventricular tachycardia/fibrillation in a patient with acute coronary artery occlusion following radiofrequency ablation within the CS. Catheter ablation is a well‐established therapy for treatment of atrial fibrillation (AF). In patients with longstanding persistent AF extensive left atrial ablation and ablation inside the coronary sinus (CS) is frequently performed. Perimitral flutter following AF ablation is the most common form of left atrial macroreentry, especially in patients with previous ablation of complex fractionated electrograms and incomplete linear lesion sets within the left atrium. Successful ablation of this type of tachycardia is generally difficult and in about 60–70% patients requires additional ablation within the CS to achieve termination of tachycardia or/and left atrial isthmus (LAI) block. A limited number of case reports have been published describing acute coronary artery occlusion during or immediately after LAI ablation within the CS. This case exhibits a potential lethal risk of radiofrequency ablation within the CS.     

Study Design of the Man and Machine Trial: A Prospective International Controlled Noninferiority Trial Comparing Manual with Robotic Catheter Ablation for Treatment of Atrial Fibrillation

Study Design of the Man and Machine Trial. Background: Pulmonary vein isolation (PVI) has become the cornerstone procedure for the treatment of symptomatic drug‐resistant atrial fibrillation (AF). At the present time, circumferential PVI (CPVI) using irrigated radiofrequency (RF) is the mostly used ablation technique. However, for CPVI, precise catheter navigation and excellent catheter stability is crucial thereby requiring experienced operators. Robotic navigation systems have been introduced to facilitate catheter navigation and to improve catheter stability, therefore potentially increasing procedural success and making CPVI accessible to less experienced operators. To date, no prospective randomized trial has evaluated the efficacy and safety of CPVI using RNS compared to manually performed ablation. Methods: In this prospective international multicenter noninferiority trial, 258 patients with either paroxysmal or short‐standing persistent AF will be randomized for comparison of PVI using either manual or robotic ablation. In all patients, CPVI will be performed using irrigated RF ablation in combination with a 3D mapping system. The primary endpoint of the trial is the absence of AF or atrial tachycardia without antiarrhythmic drug therapy during 12‐month follow‐up. Secondary endpoints will be evaluation of periprocedural complications and procedural data such as procedure time, fluoroscopy time, as well as the incidence of esophageal injury assessed by endoscopy within 48 hours after the procedure. Conclusion: The “Man and Machine Trial” is the first prospective international randomized controlled multicenter noninferiority trial to compare manually performed CPVI with robotically navigated CPVI, evaluating both the safety and efficacy of the 2 techniques during a 12‐month follow‐up period. (J Cardiovasc Electrophysiol, Vol. 24, pp. 40‐46, January 2013)     

Catheter Ablation of Long‐Standing Persistent Atrial Fibrillation: A Lesson from Circumferential Pulmonary Vein Isolation

Catheter Ablation of Long‐Standing Persistent AF. Introduction: Circumferential pulmonary vein isolation (CPVI) is associated with a high success rate in patients with paroxysmal and persistent atrial fibrillation (AF). However, in patients with long‐standing persistent AF, the ideal ablation strategy still remains a matter of debate. Methods and Results: Two‐hundred and five patients underwent catheter ablation for long‐standing persistent AF defined as continuous AF of more than 1‐year duration. In a first step, all patients underwent CPVI. If direct‐current cardioversion failed following CPVI, ablation of complex fractionated atrial electrograms (CFAEs) was performed. The goal was conversion into sinus rhythm (SR) or, alternatively, atrial tachycardia (AT) with subsequent ablation. A total of 340 procedures were performed. CPVI alone was performed during 165 procedures in 124 of 205 (60.5%) patients. In the remaining 81 patients, additional CFAE ablation was performed in 45, left linear lesions for recurrent ATs in 44 and SVC isolation in 15 patients, respectively, resulting in inadvertent left atrial appendage isolation in 9 (4.4%) patients. After the initial ablation procedure, 67 of 199 patients remained in SR during a mean follow‐up of 19 ± 11 months. Six patients were lost to follow‐up. After a mean of 1.7 ± 0.8 procedures, 135 of 199 patients (67.8%) remained in SR. Eighty‐six patients (43.2%) remained in SR following CPVI performed as the sole ablative strategy. Conclusions: CPVI alone is sufficient to restore SR in 43.2% of patients with long‐standing persistent AF. Multiple procedures and additional ablation strategies with a significant risk of inadvertent left atrial appendage isolation are often required to maintain stable SR. (J Cardiovasc Electrophysiol, Vol. 21, pp. 1085‐1093)     

Persistence of Pulmonary Vein Isolation After Robotic Remote‐Navigated Ablation for Atrial Fibrillation and its Relation to Clinical Outcome

Robotic Remote Ablation for AF . Aims: A robotic navigation system (RNS, Hansen?) has been developed as an alternative method of performing ablation for atrial fibrillation (AF). Despite the growing application of RNS‐guided pulmonary vein isolation (PVI), its consequences and mechanisms of subsequent AF recurrences are unknown. We investigated the acute procedural success and persistence of PVI over time after robotic PVI and its relation to clinical outcome. Methods and Results: Sixty‐four patients (60.7 ± 9.8 years, 53 male) with paroxysmal AF underwent robotic circumferential PVI with 3‐dimensional left atrial reconstruction (NavX?). A voluntary repeat invasive electrophysiological study was performed 3 months after ablation irrespective of clinical course. Robotic PVI was successful in all patients without complication (fluoroscopy time: 23.5 [12–34], procedure time: 180 [150–225] minutes). Fluoroscopy time demonstrated a gradual decline but was significantly reduced after the 30th patient following the introduction of additional navigation software (34 [29–45] vs 12 [9–17] minutes; P < 0.001). A repeat study at 3 months was performed in 63% of patients and revealed electrical conduction recovery in 43% of all PVs. Restudied patients without AF recurrence (n = 28) showed a significantly lower number of recovered PVs (1 (0–2) vs 2 (2–3); P = 0.006) and a longer LA‐PV conduction delay than patients with AF recurrences (n = 12). Persistent block of all PVs was associated with freedom from AF in all patients. At 3 months, 67% of patients were free of AF, while reablation of recovered PVs led to an overall freedom from AF in 81% of patients after 1 year. Conclusion: Robotic PVI for PAF is safe, effective, and requires limited fluoroscopy while yielding comparable success rates to conventional ablation approaches with PV reconduction as a common phenomenon associated with AF recurrences. (J Cardiovasc Electrophysiol, Vol. 21, pp. 1079‐1084)