Amish S. Dave

Ethanol infusion in the vein of Marshall facilitates mitral isthmus ablation

BACKGROUNDnTreatment of perimitral flutter (PMF) requires bidirectional mitral isthmus (MI) block, which can be difficult with radiofrequency ablation (RFA). The vein of Marshall (VOM) is located within the MI.nnnOBJECTIVEnTo test whether VOM ethanol infusion could help achieve MI block.nnnMETHODSnPerimitral conduction was studied in patients undergoing ablation of atrial fibrillation. Group 1 included 50 patients with a previous atrial fibrillation ablation undergoing repeat ablation, 30 of whom had had MI ablation. Spontaneous (8 of 50) or inducible PMF (21 of 50) was confirmed by activation mapping. Group 2 included 21 patients undergoing de novo VOM ethanol infusion. The VOM was cannulated with a quadripolar catheter for pacing and with an angioplasty balloon to deliver up to four 1-mL infusions of 98% ethanol. Voltage maps were created before and after VOM ethanol infusion. Bidirectional MI block was verified by differential pacing. RFA times required to achieve it were assessed.nnnRESULTSnIn group 1, VOM ethanol infusion acutely terminated PMF in 5 of 29 patients. RFA needed to achieve bidirectional MI block was 2.2 ± 1.6 minutes. Presence of PMF or previous MI ablation did not affect RFA times. In group 2, RFA needed to achieve bidirectional MI block was 2.0 ± 1.6 minutes (P = NS). Five patients had bidirectional MI block achieved solely by VOM ethanol infusion without RFA. In both groups, ablation after VOM ethanol infusion was required in the annular aspect of the MI. There were no acute complications.nnnCONCLUSIONnVOM ethanol infusion is useful in the treatment of PMF and assists in reliably achieving bidirectional MI block.

Ethanol Infusion in the Vein of Marshall Leads to Parasympathetic Denervation of the Human Left Atrium: Implications for Atrial Fibrillation

OBJECTIVESnThis study sought to determine whether ethanol infusion in the vein of Marshall (VOM) can ablate intrinsic cardiac nerves (ICN).nnnBACKGROUNDnICN cluster around the left atrial epicardium and are implicated in the genesis of atrial fibrillation (AF).nnnMETHODSnPatients undergoing catheter AF ablation underwent adjunctive ethanol injection in the VOM. A multipolar catheter was introduced in the VOM and used for high-frequency stimulation (HFS), either as HFS with P-wave synchronized (SynchHFS), 30 pulses, 100 Hz (nxa0= 8) or as HFS with 3 to 10 s bursts (BurstHFS), 33 Hz (nxa0=xa072) at 25 mA for 1-ms duration. Atrioventricular (AV) nodal conduction slowing (asystole >2 s or R-R interval prolongation >50%) and AF inducibility were assessed before and after VOM ethanol infusion. Up to 4xa01-ml infusions of 98% ethanol were delivered via an angioplasty balloon in the VOM.nnnRESULTSnSynchHFS induced AF in 8 of 8 patients. In 4 of 8 AF initiated spontaneously without VOM capture. No parasympathetic responses were elicited by SynchHFS. BurstHFS was performed in 32 patients undergoing de novo AF ablation (Group 1)xa0and 40 patients undergoing repeat ablation (Group 2). Parasympathetic responses were found in all 32 Group 1 patients and in 75% of Group 2 patients. After VOM ethanol infusion, parasympathetic responses were abolished in allxa0patients (both groups). There were no acute complications related to VOM ethanol infusion.nnnCONCLUSIONSnThe VOM contains ICN that connect with the AV node and can trigger AF. Retrograde ethanol infusion in the VOMxa0reliably eliminates local ICN responses. The VOM is a vascular route for ICN-targeting therapies.

Robotic catheter ablation of left ventricular tachycardia: Initial experience

BACKGROUNDnCatheter ablation of ventricular tachycardia (VT) can be technically challenging due to difficulty with catheter positioning in the left ventricle (LV) and achieving stable contact. The Hansen Sensei Robotic system (HRS) has been used in atrial fibrillation but its utility in VT is unclear.nnnOBJECTIVEnThe purpose of this study was to test the technical feasibility of robotic catheter ablation of LV ventricular tachycardia (VT) using the HRS.nnnMETHODSnTwenty-three patients underwent LV VT mapping and ablation with the HRS via a transseptal, transmitral valve approach. Nineteen patients underwent substrate mapping and ablation (18 had ischemic cardiomyopathy, 1 had an apical variant of hypertrophic cardiomyopathy). Four patients had focal VT requiring LV VT mapping and ablation. Procedural endpoints included substrate modification by endocardial scar border ablation and elimination of late potentials, or elimination of inducible focal VT.nnnRESULTSnMapping and ablation were entirely robotic without requiring manual catheter manipulation in all patients and reaching all LV regions with stable contact. Fluoroscopy time of the LV procedure was 22.2 ± 11.2 minutes. Radiofrequency time was 33 ± 21 minutes. Total procedural times were 231 ± 76 minutes. Complications included a left groin hematoma (opposite to the HRS sheath), 1 pericardial effusion without tamponade that was drained successfully, and transient right ventricular failure in a patient with previous left ventricular assist device. At 13.4 ± 6.7 months of follow-up (range 1-19 months), recurrence of VT occurred in 3 of 23 patients.nnnCONCLUSIONnOur initial experience suggests that the HRS allows successful mapping and ablation of LV VT.

Role of the vein of Marshall in atrial fibrillation recurrences after catheter ablation: Therapeutic effect of ethanol infusion

Vein of Marshall Ethanol in Recurrent AF.

Detection of LA and LAA Thrombus by CMR in Patients Referred for Pulmonary Vein Isolation

OBJECTIVESnThe goal of this study was to evaluate the diagnostic performance of a comprehensive, multicomponent cardiac magnetic resonance (CMR) study for assessment of left atrial (LA) and left atrial appendage (LAA) thrombus.nnnBACKGROUNDnPre-operative evaluation for pulmonary vein isolation (PVI) typically requires tomographic imaging to define pulmonary venous anatomy and transesophageal echocardiogram (TEE) to assess for the presence of LA/LAA thrombus. CMR is increasingly being used to define pulmonary venous anatomy before PVI. Limited data are available onxa0the utility of a multicomponent CMR protocol in assessing LA/LAA thrombus.nnnMETHODSnWe studied patients who underwent multicomponent CMR for evaluation of pulmonary venous anatomy before PVI and underwent TEE within 7 days. LA and LAA thrombi were evaluated by using CMR as follows: 1) cine-CMR; 2) contrast-enhanced magnetic resonance angiography; and 3) equilibrium phase delayed enhancement (DE) CMR with axa0long inversion time (TI) of 600 ms (long TI DE-CMR). Components of the CMR study were evaluated for diagnostic performance for detection of LA or LAA thrombus using TEE as the reference standard.nnnRESULTSnDuring the study period, 261 patients were assessed. The median CHA2DS2VASc (congestive heart failure, hypertension, agexa0≥75 years, diabetes mellitus, stroke/transient ischemic attack, vascular disease, age 65 to 74 years, sex category) score was 2, and 73.6% of patients were undergoing anticoagulation therapy. CMR and TEE were performed within 1.3 ± 2.3 days. LA/LAA thrombi were discovered in 9 patients (3.5%) by using TEE. Among the CMR techniques performed, long TI DE-CMR had the highest diagnostic accuracy (99.2%), sensitivity (100%), and specificity (99.2%), followed by contrast-enhanced magnetic resonance angiography (accuracy 94.3%; sensitivity 66.7%; and specificity 95.2%) and cine-CMR (accuracy 91.6%; sensitivity 66.7%; and specificity 92.5%).nnnCONCLUSIONSnIn patients referred for PVI, CMR could be a single complete diagnostic study for assessment of pulmonary venous anatomy as well as presence of LA/LAA thrombi, thus reducing the number of pre-operative tests before PVI. Long TI DE-CMR has the best diagnostic performance and should be used for the detection of LA/LAA thrombi.

Retrograde coronary venous ethanol infusion for ablation of refractory ventricular tachycardia

Background—Radiofrequency ablation (RFA) of ventricular tachycardia (VT) can fail because of inaccessibility to the VT substrate. Transarterial coronary ethanol ablation can be effective but entails arterial instrumentation risk. We hypothesized that retrograde coronary venous ethanol ablation can be an alternative bail-out approach to failed VT RFA. Methods and Results—Out of 334 consecutive patients undergoing VT/premature ventricular contraction ablation, 7 patients underwent retrograde coronary venous ethanol ablation. Six out of 7 patients had failed RFA attempts (including epicardial in 3). Coronary venogram-guided venous mapping was performed using a 4F quadripolar catheter or an alligator-clip–connected angioplasty wire. Targeted veins included those with early presystolic potentials and pace-maps matching VT/premature ventricular contraction. An angioplasty balloon (1.5–2×6 mm) was used to deliver 1 to 4 cc of 98% ethanol into a septal branch of the anterior interventricular vein in 5 patients with left ventricular summit VT, a septal branch of the middle cardiac vein, and a posterolateral coronary vein (n=1 each). The clinical VT was successfully ablated acutely in all patients. There were no complications of retrograde coronary venous ethanol ablation, but 1 patient developed pericardial and pleural effusion attributed to pericardial instrumentation. On follow-up of 590±722 days, VT recurred in 4 out of 7 patients, 3 of whom were successfully reablated with RFA. Conclusions—Retrograde coronary venous ethanol ablation is safe and feasible as a bail-out approach to failed VT RFA, particularly those originating from the left ventricular summit.

Left Atrial Appendage Remodeling after Lariat Left Atrial Appendage Ligation

Background—Left atrial appendage (LAA) ligation with the Lariat device is being used for stroke prevention in atrial fibrillation. Residual leaks into the LAA are commonly reported after the procedure. Little is known about the anatomic LAA remodeling after Lariat ligation. Methods and Results—In an exploratory study, we evaluated LAA 3-dimensional geometry via computed tomographic scan in 31 consecutive patients before Lariat closure and after a minimum of 30 days post procedure. Thirteen patients were classified as unfavorable cases based on anatomic criteria. Our population had an average age of 70±12 years, a mean CHADS2 (congestive heart failure, hypertension, age>75, diabetes mellitus, history of stroke) score of 3.2±1.2, a mean CHADS2VASC (CHADS2 in addition to female sex, ages 65–75, as well as double impact of age >75, vascular disease) of 4.2±1.5, and a mean HASBLED (hypertension, abnormal renal/liver function, stroke, bleeding predisposition/history, labile international normalized ratio, elderly, drugs/alcohol) bleeding score of 4.0±1.1. Successful suture deployment was achieved in all cases, but 3 patients had intraprocedural residual flow into the LAA (leak). On follow-up, 10 patients (32%) had recanalized residual LAA cavities, which were morphologically similar to the original LAA, albeit significantly smaller in volume (22.5±13.3% of the original volume). Recanalization was not associated with age, sex, comorbid conditions, stroke or bleeding risk scores, follow-up interval, baseline LAA volume, or morphology. Unfavorable cases had anatomic outcomes comparable with those of the anatomically favorable population. No patients have exhibited thromboembolism after 842±338 days post ligation. Conclusions—Incomplete LAA ligation after Lariat is common. However, the remodeled LAA cavity is dramatically reduced. Diminished cavity size and tightening of the LAA orifice may play a role in the reduction of thrombus formation.

The Human Left Atrial Venous Circulation as a Vascular Route for Atrial Pharmacological Therapies: Effects of Ethanol Infusion

OBJECTIVESnThis study catalogued the human venous left atrium (LA) circulation system and the ablative effects of ethanol in different branches.nnnBACKGROUNDnVascular routes to target the LA could have significant therapeutic potential. Beyond the vein of Marshall (VOM), the fluoroscopic LA venous anatomy has not been described.nnnMETHODSnPatients undergoing ethanol infusion in the VOM as adjunctive therapy to atrial fibrillation (AF) catheter ablation were included in this study. Balloon occlusion venograms of the VOM and other LA veins were obtained in 218xa0patients.nnnRESULTSnSequentially from the coronary sinus (CS) ostium, LA veins included: 1) proximal septal vein draining the inferior septum; 2) inferior LA vein in the annular inferior LA; 3) VOM; 4) LA appendage vein; and 4) anterior LA vein. Additionally, venous sinuses not connected to the CS included roof veins and posterior wall veins, which drained into the right and left atria, respectively. Venous connections between LA veins through capillaries and with pulmonary veins were abundant. Extracardiac collateral vessels were present in 38 patients (17.4%). Ethanol infusion in LA veins led to tissue ablation in their corresponding regions.nnnCONCLUSIONSnThe atrial venous anatomy is amenable to selective cannulation. Consistent anatomical patterns arexa0present.xa0Targeting atrial tissues through atrial veins can be used for therapeutic purposes.

Strategies for phrenic nerve preservation during ablation of inappropriate sinus tachycardia

BACKGROUNDnRadiofrequency (RF) ablation can alleviate drug-refractory inappropriate sinus tachycardia (IST). However, phrenic nerve (PN) injury and other complications limit its use.nnnOBJECTIVEnThe purpose of this study was to characterize the maneuvers used to avoid PN injury and the long-term clinical outcomes.nnnMETHODSnThe study consisted of a retrospective analysis of consecutive patients who underwent ablation for IST.nnnRESULTSnRF ablation was performed on 13 consecutive female patients with drug-refractory IST. Eleven patients exhibited PN capture at desired ablation sites. In 1 patient, PN capture was not continuous throughout the respiratory cycle and ventilation holding sufficed to avoid PN injury. In 10 patients, pericardial access (PA) and balloon insertion was required. Initially (n = 4) a posterior PA was used, which was replaced by an anterior PA in the subsequent 6 cases. PA to optimal balloon positioning time was significantly lower in anterior vs posterior PA (16.3 ± 6 minutes vs 58 ± 21.3 minutes, P = .01), as was fluoroscopy time (15.66 ± 16.72 min vs 35.9 ± 1.8 min, P = .03). RF ablation successfully reduced sinus rate to <90 bpm in 13 of 13 patients. Procedure times and total RF times were not significantly different in anterior vs posterior PA. Major complications occurred in 2 patients, including unremitting pericardial bleeding requiring open-chested repair in 1 patient and sinus pauses mandating pacemaker implantation in the other patient. Long-term symptom control after follow-up of 811 ± 42 days was successful in 84.6%.nnnCONCLUSIONnVentilation holding and/or pericardial balloon insertion are frequently warranted in IST ablation. Anterior PA appears to facilitate the procedure over posterior PA.

The Tell-Tale Heart (Now, Optically Mapped)⁎

In Edgar Allan Poes short story ([1][1]) published in 1843, a nameless narrator murders an old man, dismembers the body, and then hides it under the floorboards. When the police come to investigate, the murderer becomes quickly tormented by what he perceives is the sound of the dead mans heartbeat