Surgical cryoablation for ventricular tachyarrhythmia arising from the left ventricular outflow tract region.

BACKGROUND Ventricular arrhythmias (VAs) from the left ventricular outflow tract (LVOT) region can be inaccessible for ablation because of epicardial fat or overlying coronary arteries. OBJECTIVE We describe surgical cryoablation of this type of VA. METHODS From March 2009 to 2014, 190 consecutive patients with VAs originating from the LVOT underwent ablation at our institution. Four patients (2%) underwent surgical cryoablation for highly symptomatic VAs after failing catheter ablation. RESULTS In all patients, endocardial or percutaneous epicardial mapping was consistent with origin in the LVOT. In 2 patients, the points of earliest activation during VAs were marked with a bipolar pacing lead in the overlying cardiac vein for guidance during surgery. Surgical cryoablation was successful in 3 of the 4 patients. The fourth patient subsequently had successful endocardial catheter ablation. During a mean follow-up of 22 ± 16 months (range 4-42 months), all patients showed abolition of or marked reduction in symptomatic VA. However, 1 patient subsequently required percutaneous intervention to the left anterior descending coronary artery; another developed progressive left ventricular systolic dysfunction caused by nonischemic cardiomyopathy; and a third patient underwent permanent pacemaker implantation because of complete atrioventricular block after concomitant aortic valve replacement. CONCLUSION Surgical cryoablation is an option for highly symptomatic drug-resistant VAs emanating from the LVOT region. Despite extensive preoperative mapping, the procedure is not effective for all patients, and coronary injury is a risk.

Better outcome of ablation for sustained outflow-tract ventricular tachycardia when tachycardia is inducible.

AIMS In patients presenting with spontaneous sustained ventricular tachycardia (VT) from the outflow-tract region without overt structural heart disease ablation may target premature ventricular contractions (PVCs) when VT is not inducible. We aimed to determine whether inducibility of VT affects ablation outcome. METHODS AND RESULTS Data from 54 patients (31 men; age, 52 ± 13 years) without overt structural heart disease who underwent catheter ablation for symptomatic sustained VT originating from the right- or left-ventricular outflow region, including the great vessels. A single morphology of sustained VT was inducible in 18 (33%, SM group) patients, and 11 (20%) had multiple VT morphologies (MM group). VT was not inducible in 25 (46%) patients (VTni group). After ablation, VT was inducible in none of the SM group and in two (17%) patients in the MM group. In the VTni group, ablation targeted PVCs and 12 (48%) patients had some remaining PVCs after ablation. During follow-up (21 ± 19 months), VT recurred in 46% of VTni group, 40% of MM inducible group, and 6% of the SM inducible group (P = 0.004). Analysis of PVC morphology in the VTi group further supported the limitations of targeting PVCs in this population. CONCLUSION Absence of inducible VT and multiple VT morphologies are not uncommon in patients with documented sustained outflow-tract VT without overt structural heart disease. Inducible VT is associated with better outcomes, suggesting that attempts to induce VT to guide ablation are important in this population.

Papers presented at the Census Tract Conference on September 10, 1965 at Philadelphia, Pa.

Mode of access: Internet.

Joannes Matthaeus and his tract "De rerum inventoribus".

Pt. I, read before the Society Dec. 4, 1901; Pt. II, read Dec. 18, 1916.

England and France in the fifteenth century. The contemporary Franch tract entitled "The debate between the heralds of France and England," presumed to have been written by Charles, duke of Orleans: translated for the first time into English; with an introduction, notes, an inquiry into the authorship, etc.

Mode of access: Internet.

Fabian tract /

Latest issue consulted: 541, published in 1990.

Tract.

No. 5 included in English history pamphlets, vol. 22.

Census tract location guide; Detroit standard metropolitan statistical area (1960 census tracts and population from the U.S. Bureau of the census)

Mode of access: Internet.

A treatise on biliary concretions, or, stones in the gall-bladder and ducts /

Mode of access: Internet.

Doctoris Ioannis de Selva iuris utriusque doctoris, quondam in Suprema Parisiensi Curia Consilarij, & tandem, ut alij existimant, primi Praesidis Tract. de Beneficio : cum notis et quibusdam additionibus celebris in magno Regis Consilio Aduocati, praxis beneficiariae peritissimi.

Mode of access: Internet.

An American tract for the times : being an humble but earnest plea in behalf of common sense /

Tryon and Charvat

Census tract project, Flint and Genesee County.

Cover title.

A tract upon tomb-stones; or Suggestions for the consideration of persons intending to set up that kind of monument to the memory of deceased friends.

Author's name on cover.

The articles treated on in Tract 90 reconsidered : and their interpretation vindicated in a letter to the Rev. R.W. Jelf ; with an appendix from Abp. Ussher on the difference between ancient and modern addresses to saints /

Tract no. 90, by J.H. Newman, has title, Remarks on certain passages in the Thirty-nine articles.

The objects and limits of operations for cancer : with special reference to cancer of the breast, mouth and throat, and intestinal tract : being the Lettsomian lecture for 1896 /

"Reprinted from the Transactions of the Medical Society of London, vol. xix"--T.p. verso