PubMed Health⌕ Search

Biomedical subjects

Patrick M McCarthy

Publications and source records attributed to Patrick M McCarthy.

At least 37 records · Page 2Linked to original sources
PubMed2005

Myocardial compliance was not altered after acute induction of atrial fibrillation in sheep.

BACKGROUND: Although left ventricular (LV) contractility in atrial fibrillation (Af) is known to change in a beat-to-beat fashion, little is known about the changes in LV compliance in Af. MATERIAL/METHODS: We experimentally induced tachycardic Af (average heart rate - 154 beats per minute) in 18 sheep. LV volume and pressure were simultaneously monitored using a conductance catheter. LV end-diastolic volume (V(ED)) and pressure (P(ED)) were plotted in a beat-to-beat fashion and fitted to the following exponential equation (P(ED)=gamma x e(b x V(ED))) in each animal. A random effects model was constructed to determine if the intercepts and slopes differ. RESULTS: In all animals, those plots after the induction of Af fit quite well to the exponential function (r=0.834+/-0.184) by gating short preceding interval (RR1) beats. By simply taking the natural logarithm of both sides in the equation, the linear relationship (ln(P(ED)) =alpha+ betaxV(ED), where a = lng) was observed in all animals before (normal sinus rhythm, NSR) and after the induction of Af. Only two of 18 intercepts and four of 18 slopes deviate between NSR and Af. Most interestingly, the random effects model clearly detailed that the average animal had intercepts and slopes that were not discernibly different between NSR and Af. CONCLUSIONS: Unlike LV contractility, myocardial compliance did not change after the acute induction of Af. These interesting results may give us insights into the understanding of the physiology in acute rapid Af.

Animals↗
PubMed2005

Tricuspid valve tethering predicts residual tricuspid regurgitation after tricuspid annuloplasty.

BACKGROUND: Tricuspid valve (TV) annuloplasty is recommended for functional tricuspid regurgitation (TR), which is caused by TV annulus dilatation and tethering of the leaflets. However, the impact of TV deformations on the outcome of TV annuloplasty remains unknown. The goal of this study was to investigate the relationship between preoperative TV deformation and residual TR after TV annuloplasty. METHODS AND RESULTS: Two hundred sixteen patients with functional TR had 2D echocardiography before and after TV annuloplasty. Right ventricular fractional area change and left ventricular ejection fraction were determined with the apical views. Minimal TV annulus diameter was determined by frame-by-frame analysis. The distance of TV tethering was measured from the annulus plane to the coaptation point and tethering area by tracing the leaflets from the annulus plane. TR severity was determined by the ratio of the maximal jet area to the corresponding right atrial area. The severity of residual TR was associated with age, right and left ventricular dysfunction, tethering distance and area, and severity of preoperative TR (all P<0.05). TV annular dimension was not associated with outcome of TV annuloplasty. Multivariate analysis revealed that age, tethering distance, and severity of preoperative TR (all P<0.001) were independent parameters predicting residual TR. The sensitivity and specificity in predicting residual TR after surgery were 86% and 80% for tethering distances >0.76 cm and 82% and 84% for tethering areas >1.63 cm2, respectively. CONCLUSIONS: Severe TV tethering predicted residual TR after TV annuloplasty, whereas preoperative TV annular dimension was not associated with outcome of TV annuloplasty.

Aged↗
PubMed2005

Nontransplant surgical alternatives for heart failure.

Heart failure is a tremendous burden on society, and on the health care system in particular. Historically, medical treatments have been the only therapies available because patients were felt to be too high risk to undergo conventional cardiac surgical procedures. Cardiac transplantation remains an established therapy for certain patients with end-stage heart failure but it is limited by donor availability and the need for lifelong immunosuppression. Recent advances in myocardial protection, operative techniques, and perioperative care have made it possible for conventional surgery, such as coronary bypass, ventricular reconstruction, and valve repair, to be offered to many patients with advanced heart failure with good short- and long-term results. In 2005, few patients are inoperable.

Journal Article↗
PubMed2005

Bench repair of donor aortic valve with minimal access orthotopic heart transplantation.

While the number of people waiting heart transplantation increases, the number of organ donors decreases. This shrinking donor pool has prompted reassessment of donor selection for heart transplantation. Bench repair of a donor aortic valve was performed before minimal access orthotopic heart transplantation. Aortic insufficiency in the structurally normal tricuspid aortic valve was due to annular dilatation and was corrected with subcommissural annular plication. The postoperative period was uneventful. Follow-up at 4.5 years showed good results and no evidence of aortic regurgitation.

Aortic Valve↗
PubMed2005

Importance of moderate ischemic mitral regurgitation.

BACKGROUND: The importance of moderate ischemic mitral regurgitation in patients presenting for coronary artery bypass grafting (CABG) is controversial. Therefore, we tracked the course of unrepaired moderate ischemic mitral regurgitation after CABG surgery alone, identified factors associated with worsening postoperative ischemic mitral regurgitation, and assessed the impact of unrepaired moderate ischemic mitral regurgitation on survival. METHODS: From 1980 to 2000, 467 patients with moderate ischemic mitral regurgitation underwent CABG alone. The course of unrepaired mitral regurgitation was estimated by a longitudinal analysis of 267 follow-up echocardiograms from 156 patients. The survival impact of moderate ischemic mitral regurgitation was determined among propensity-matched patients with and without ischemic mitral regurgitation. RESULTS: Mitral regurgitation was dynamic early postoperatively. Immediately postoperatively, it was absent or mild in 73% and severe in 6%; by 6 weeks, these figures were 40% and 22%, respectively. The course of postoperative mitral regurgitation was not associated with the preoperative extent of coronary artery disease or left ventricular dysfunction. Five-year survival of matched bypass patients without ischemic mitral regurgitation was 85% compared with 73% for patients with moderate ischemic mitral regurgitation (p = 0.003). CONCLUSIONS: Moderate ischemic mitral regurgitation does not reliably resolve with CABG surgery alone and is associated with reduced survival. Therefore, a mitral valve procedure may be warranted for such patients presenting for CABG. A randomized trial comparing strategies of revascularization with mitral valve repair and revascularization alone is required to determine optimal treatment.

Adult↗
PubMed2005

Ischemic mitral regurgitation: impact of the left ventricle and mitral valve in patients with left ventricular systolic dysfunction.

BACKGROUND: Mitral regurgitation (MR) is a common complication of ischemic heart disease, and its presence portends adverse outcomes. As the exact mechanisms of ischemic MR are not well defined, we characterized left ventricular global geometry, regional function, and regional myocardial scarring, in addition to mitral valve apparatus geometry, using magnetic resonance imaging (MRI) of ischemic heart disease patients with left ventricular dysfunction and varying degrees of ischemic MR. METHODS: Sixty patients with varying degrees of MR (none, mild, moderate, and severe) determined by echocardiography and referred for MRI assessment of ischemic heart disease were included. Left ventricular geometric, functional, and scar measurements in addition to mitral valve geometric measurements were evaluated. RESULTS: Clinical characteristics found to be significant predictors of degree of MR included severity of coronary artery disease (p < 0.05), completeness of myocardial perfusion (p < 0.005), and average systolic blood pressure (p < 0.05). Mitral systolic tenting area (p < 0.0001) in a statistical model with scarring of the anterior-lateral region (p < 0.05) proved to be the most powerful predictor of MR severity (r2 = 0.31). Mitral annular dilatation in the anterior-posterior direction (p < 0.0001) and diminished LV systolic function (p < 0.005) were important determinants of mitral systolic tenting area (r2 = 0.57). CONCLUSIONS: Mitral tenting in combination with regional left ventricular myocardial scarring are important mechanisms to the development of ischemic MR. Surgical annuloplasty addresses mitral tenting, but has little impact on the effect of regional scarring. Moderate-to-severe ischemic MR develops in patients with regional scarring of the anterior-lateral and inferior-posterior regions, and new surgical developments should take this into account.

Aged↗
PubMed2005

Ischemic versus degenerative mitral regurgitation: does etiology affect survival?

BACKGROUND: Ischemic mitral regurgitation (MR) is associated with poor survival and degenerative MR with excellent survival. We hypothesized that in some patients with degenerative MR requiring concomitant coronary artery bypass grafting (CABG), ischemic disease would dominate prognosis, resulting in survival as poor as in patients with ischemic MR. Thus, we (1) determined survival impact of etiology (degenerative vs ischemic) after combined mitral valve repair and CABG and (2) explored survival differences within etiology groups. METHODS: From 1985 to 2003, 710 patients underwent mitral valve repair for degenerative MR and concomitant CABG (two diseases); 400 patients had mitral annuloplasty and CABG for functional ischemic MR (one disease). Patients were propensity-matched on demography, symptoms, comorbidities, coronary artery disease, and left ventricular function. Survival was compared between matched groups and within groups. RESULTS: Compared with patients with degenerative MR, those with ischemic MR had more extensive coronary artery disease, worse ventricular function, more comorbidities, and more symptoms (p < 0.05). Unadjusted 5-year survivals were 64% and 82% for patients with ischemic and degenerative MR, respectively. However, 123 ischemic and degenerative MR matched pairs had equivalently poor 5-year survival (p > 0.9), 66% and 65%, respectively. Among patients with degenerative MR, survival varied widely, depending largely on ischemic burden and extent of left ventricular dysfunction. CONCLUSIONS: The large survival discrepancy between patients with ischemic and degenerative MR is attributable to differences in patient profile, particularly extent of ischemic disease and left ventricular dysfunction. Thus, ischemic and degenerative MR patients with equivalent characteristics have equivalently poor survival.

Aged↗
PubMed2005

Giant flow reversal in pulmonary venous flow as a possible mechanism for asynchronous pacing-induced heart failure.

BACKGROUND: Mechanistic roles of the immediate increase in left atrial (LA) pressure in pacing-induced congestive heart failure have not been clearly understood. We evaluated the impact of asynchronous rapid ventricular pacing on LA hemodynamics in this model. METHODS: Transthoracic and transesophageal echocardiography and hemodynamic assessment were performed in 23 healthy mongrel dogs. Data were acquired before and 5 minutes after initiation of rapid right ventricular pacing (200/min). RESULTS: At 5 minutes after initiation of the pacing, giant pulmonary venous (PV) flow reversal (-76 cm/s) was observed in association with 1:1 ventriculoatrial conduction or complete atrioventricular dissociation. This giant PV flow reversal corresponded to an inappropriately timed atrial contraction, especially during systole. Cardiac output (3.21 vs 2.00 L/min, P < .001) was decreased corresponding to the decrease in the forward blood volumes as described by decrease in the Doppler left ventricular (LV) outflow (8.99 vs 4.73 cm, P < .0001), mitral inflow (6.89 vs 3.19 cm, P < .0001), and PV flow (14.15 vs 7.22 cm, P < .0001) velocity integrals. As a result, there was a marked elevation of the mean pulmonary capillary wedge (9.1 vs 17.1 mm Hg, P < .001) and LV end-diastolic (8.2 vs 17.4 mm Hg, P < .01) pressures leading to congestive heart failure. CONCLUSIONS: The giant PV flow reversal seen during asynchronous rapid right ventricular pacing corresponds to an inappropriate atrial contraction, immediately elevates LA pressure, and may initially promote congestive heart failure. The increase in LV end-diastolic pressure associated with decreased LV ejection fraction caused decrease in the LV filling volume leading to further increase in the LA pressure. This sustained marked elevation in the LA pressure and LV end-diastolic pressure could contribute to the heart failure process.

Animals↗
PubMed2005

Mitral annulus size links ventricular dilatation to functional mitral regurgitation.

We compared the impact of annulus size and valve deformation (tethering) on mitral regurgitation in the animal dilated cardiomyopathy model, and assessed if acute left ventricular volume changes affect mitral annulus dimensions. We performed 3-dimensional echocardiography in 30 open-chest dogs with pacing-induced cardiomyopathy. Mitral annulus area was calculated from its two orthogonal diameters, whereas valve tethering was quantified by valve tenting area measurement. Mitral valve regurgitant volume showed the highest correlation with annulus area (r = 0.64, P < .001), left atrial volume (r = 0.40, P < .01), and left ventricular end-diastolic volume (r = 0.37, P < .01). Regurgitant volume showed poorer correlation with valve tethering in both septolateral and intercommissural planes (r = 0.35 and r = 0.31, P < .05 for both). Annulus dimensions correlated with acute changes of left ventricular end-diastolic volume (r = 0.68, P = .002). Mitral annulus dilation is the strongest predictor of functional mitral regurgitation in this animal dilated cardiomyopathy model.

Animals↗
PubMed2005

Surgical ablation of atrial fibrillation with bipolar radiofrequency as the primary modality.

OBJECTIVES: In studying cardiac surgical patients undergoing atrial fibrillation ablation with bipolar radiofrequency, we sought to (1) quantify the time-related prevalence of atrial fibrillation postoperatively and identify its risk factors and (2) determine time-related ablation failure and its risk factors. METHODS: From November 2001 to January 2004, 513 patients underwent atrial fibrillation ablation (bipolar radiofrequency alone or with cryothermy) and other cardiac operations. Rhythm documented on 3495 postoperative electrocardiograms was used to estimate the prevalence of and risk factors for atrial fibrillation across time. Ablation failure was defined as occurrence of atrial fibrillation any time beyond 6 months after operation. RESULTS: Prevalence of postoperative atrial fibrillation peaked at about 1 month, decreased to 13% at 6 months, and gradually increased thereafter. Risk factors associated with increased prevalence varied by time period and included older age ( P = .004) for early occurrence, lesion set in permanent atrial fibrillation ( P = .02) for late occurrence, and larger left atrial diameter ( P = .02) and permanent atrial fibrillation ( P < .0001) for occurrence across the entire time span. Freedom from ablation failure was 72% at 12 months. Risk factors for ablation failure included lesion set in permanent atrial fibrillation ( P = .001), longer duration of atrial fibrillation ( P = .01), and larger left atrial diameter ( P = .03). CONCLUSIONS: Bipolar radiofrequency enables extension of ablation to most cardiac surgical patients with atrial fibrillation. Recurrence is influenced by the type and duration of atrial fibrillation, choice of lesion set in permanent atrial fibrillation, and left atrial size. Early operation, careful choice of lesion set, and left atrial reduction might enhance results.

Aged↗
PubMed2005

Mitral valve stiffening in end-stage heart failure: evidence of an organic contribution to functional mitral regurgitation.

OBJECTIVE: Mitral regurgitation is a complication for many patients with congestive heart failure. Although this regurgitation is considered purely functional, we hypothesize that the alterations in cardiac geometry and function induce dysfunctional remodeling of the mitral valve, which can be demonstrated by alterations in the material behavior of the leaflets and chordae. METHODS: Mitral leaflets and chordae from 23 valves from transplant recipient hearts (11 with dilated and 12 with ischemic cardiomyopathy) and from 21 normal valves (from autopsy) were mechanically tested. RESULTS: Radially oriented anterior mitral leaflet strips from failing hearts were 61% stiffer and 23% less viscous on average than those from autopsy control hearts. The mean stiffness of circumferentially oriented anterior leaflet strips was 50% higher than that of control hearts. Leaflet extensibility was reduced 35% overall. Likewise, the failing heart chordae were an average of 16% stiffer (all P < or = .05). CONCLUSIONS: Mitral valves in congestive heart failure have significantly altered mechanics that suggest that the tissue is permanently distended and fibrotic and might be unable to stretch sufficiently to cover the valve orifice. These material changes in the valve tissues accompany the biochemical alterations in extracellular matrix composition that we have previously reported. Our finding of leaflet and chordal remodeling suggests that mitral regurgitation in patients experiencing heart failure might not be purely functional and that these mitral valves should not be considered normal. Moreover, there are implications for strategies of mitral valve surgery or percutaneous approaches in this patient population.

Chordae Tendineae↗
PubMed2005

Residual high incidence of ventricular arrhythmias after left ventricular reconstructive surgery.

OBJECTIVE: Left ventricular reconstruction is performed in patients with ischemic cardiomyopathy and akinetic or dyskinetic left ventricular regions. These patients may remain at risk for malignant ventricular arrhythmias and hence may benefit from prophylactic implantable cardioverter-defibrillators. Specific guidelines for electrophysiologic testing and implantable cardioverter-defibrillator implantation in patients undergoing left ventricular reconstruction are lacking. We aimed to assess the residual risk and timing of ventricular arrhythmias after left ventricular reconstruction to determine whether electrophysiologic risk stratification or implantable cardioverter-defibrillator implantation can be safely deferred. METHODS: Data were prospectively gathered on 217 consecutive patients with left ventricular ejection fractions less than 40% undergoing left ventricular reconstruction at our institution from 1997 to 2002. Patients were divided into 3 groups: group 1, implantable cardioverter-defibrillator present before surgery; group 2, implantable cardioverter-defibrillator implanted early after surgery; and group 3, no implantable cardioverter-defibrillator implanted. End points were all-cause mortality (censored for cardiac transplantation) and appropriate implantable cardioverter-defibrillator therapies. RESULTS: Of 217 patients (mean age, 61 +/- 10 years [mean +/- SD]), survival after a median follow-up of 381 days was 90%. Electrophysiologic studies successfully identified patients at low risk. Appropriate implantable cardioverter-defibrillator therapies occurred in 20% of group 1 and 12% of group 2. The median time to the first implantable cardioverter-defibrillator therapy from the time of left ventricular reconstruction was 43 days, and most first therapies (67%) occurred within the first 63 days. CONCLUSIONS: The early event rates (occurring in the first 90 days after left ventricular reconstruction) support the use of predischarge electrophysiologic studies, implantation of implantable cardioverter-defibrillators before discharge from the hospital, or both.

Adult↗
PubMed2004

Surgical ventricular restoration in the treatment of congestive heart failure due to post-infarction ventricular dilation.

OBJECTIVES: The purpose of this study was to test how surgical ventricular restoration (SVR) affects early and late survival in a registry of 1,198 post-anterior infarction congestive heart failure (CHF) patients treated by the international Reconstructive Endoventricular Surgery returning Torsion Original Radius Elliptical shape to the left ventricle (RESTORE)team. BACKGROUND: Congestive heart failure may be caused by late left ventricular (LV) dilation after anterior infarction. The infarcted segment is often akinetic rather than dyskinetic because early reperfusion prevents transmural necrosis. Previously, only dyskinetic areas were treated by operation. Surgical ventricular restoration reduces LV volume and creates a more elliptical chamber by excluding scar in either akinetic or dyskinetic segments. METHODS: The RESTORE group applied SVR to 1,198 post-infarction patients between 1998 and 2003. Early and late outcomes were examined, and risk factors were identified. RESULTS: Concomitant procedures included coronary artery bypass grafting in 95%, mitral valve repair in 22%, and mitral valve replacement in 1%. Overall 30-day mortality after SVR was 5.3% (8.7% with mitral repair vs. 4.0% without repair; p < 0.001). Perioperative mechanical support was uncommon (<9%). Global systolic function improved postoperatively. Ejection fraction (EF) increased from 29.6 +/- 11.0% preoperatively to 39.5 +/- 12.3% postoperatively (p < 0.001). The left ventricular end-systolic volume index (LVESVI) decreased from 80.4 +/- 51.4 ml/m(2) preoperatively to 56.6 +/- 34.3 ml/m(2) postoperatively (p < 0.001). Overall five-year survival was 68.6 +/- 2.8%. Logistic regression analysis identified EF or=80 ml/m(2), advanced New York Heart Association (NYHA) functional class, and age >or=75 years as risk factors for death. Five-year freedom from hospital readmission for CHF was 78%. Preoperatively, 67% of patients were NYHA functional class III or IV and postoperatively, 85% were class I or II. CONCLUSIONS: Surgical ventricular restoration improves ventricular function and is highly effective therapy in the treatment of ischemic cardiomyopathy with excellent five-year outcome.

Aged↗
PubMed2004

Preload-adjusted right ventricular maximal power: concept and validation.

Right ventricular (RV) maximal power (PWR(mx)) is dependent on preload. The objective of this study was to test our hypothesis that the PWR(mx) versus end-diastolic volume (EDV) relationship, analogous to the load-independent stroke work (SW) versus EDV relationship (preload-recruitable SW, PRSW), is linear, with the PWR x-axis intercept (V(0PWR)) corresponding to the PRSW intercept (V(0SW)). If our hypothesis is correct, the preload sensitivity of PWR(mx) could be eliminated by adjusting for EDV and V(0PWR). Ten dogs were instrumented with a pulmonary flow probe, micromanometers, and RV conductance catheter. Data were obtained during bicaval occlusions under various conditions and fitted to PWR(mx) = a.(EDV - V(0PWR))(beta), where a is the slope of the relationship. The PWR(mx) versus EDV relationship did not deviate from linearity (beta = 1.09, P = not significant vs. 1), and V(0PWR) correlated with V(0SW) (r = 0.93, P <0.0001). V(0PRW) was related to steady-state EDV and left ventricular end-diastolic pressure, allowing for estimation of V(0PWR) (V(0Est)) and single-beat PWR(mx) preload adjustment. Dividing PWR(mx) by the difference of EDV and V(0PWR) (PAMP(V0PWR)) eliminated preload dependency down to 50% of the baseline EDV. PWR(mx) adjustment using V(0Est) (PAMP(V0Est)) showed similar preload independency. Enhancing contractility increased PAMP(V0PWR) and PAMP(V0Est) from 176 +/- 52 to 394 +/- 205 W/ml x 10(4) and 145 +/- 51 to 404 +/- 261 W/ml x 10(4), respectively, accompanied by an increase of PRSW from 13.0 +/- 4.5 to 29.7 +/- 16.4 mmHg (all P <0.01). PAMP(V0PWR) and PAMP(V0Est) correlated with PRSW (r = 0.85; r = 0.77; both P <0.001). Numerical modeling confirmed the accuracy of our experimental data. Thus preload adjustment of PWR(mx) should consider a linear PWR(mx) versus EDV relationship with distinct V(0PWR). PAMP(V0PWR) is a preload-independent estimate of RV contractility that may eventually be determined noninvasively.

Animals↗
PubMed2004

Angiotensin II receptors from peritransplantation through first-year post-transplantation and the risk of transplant coronary artery disease.

OBJECTIVES: We evaluated whether the angiotensin II (Ang II) receptors from perioperation through one-year post-transplantation predict the transplant coronary artery disease (TCAD) progression. BACKGROUND: The role of Ang II receptors (type 1: AT(1)R; type 2: AT(2)R) in TCAD is uncertain. METHODS: We investigated 28 heart donors and the corresponding recipients. The levels of AT(1)R and AT(2)R messenger ribonucleic acid (mRNA) were examined in lymphocytes from the donor spleen and in the donor heart at one-week and one-year posttransplantation to determine their association with the progression of TCAD, measured as changes in maximal intimal thickness (CMIT) and plaque volume (CPV) by intravascular ultrasound (IVUS) examinations. RESULTS: The AT(1)R mRNA in lymphocytes from the donor spleen (CMIT: r = 0.73, p < 0.0001; CPV: r = 0.69, p < 0.0001) and in the donor hearts at one-week (CMIT: r = 0.52, p = 0.005; CPV: r = 0.56, p = 0.002) and at one-year (CMIT: r = 0.63, p < 0.0001; CPV: r = 0.43, p = 0.004) post-transplantation along with AT(2)R mRNA in the donor hearts at one-year post-transplantation (CMIT: r = 0.3, p < 0.0001; CPV: r = 0.53, p = 0.009) were univariate predictors, whereas AT(1)R mRNA in lymphocytes and in the donor hearts at one-year post-transplantation proved to be multivariate predictors of the progression of TCAD. CONCLUSIONS: These data suggest a role for Ang II receptors in the pathogenesis of TCAD and support a novel concept that TCAD may have its origin in the donor per se and may be modulated by the recipient's inherent biological factors.

Adult↗
PubMed2004

Bipolar radiofrequency to ablate atrial fibrillation in patients undergoing mitral valve surgery.

BACKGROUND: Atrial fibrillation (AF) affects 30% to 50% of patients undergoing mitral valve surgery. The optimum treatment of AF in these patients is unclear. The purpose of this study was to describe initial clinical experience using a bipolar radiofrequency clamp to facilitate AF ablation in patients undergoing mitral valve surgery. METHODS: From November 2001 through March 2003 a bipolar radiofrequency clamp was used to facilitate AF ablation in 108 patients undergoing mitral valve surgery. Preoperative AF was paroxysmal in 25%, persistent in 26%, and permanent in 49% of the patients. All patients underwent bilateral pulmonary vein isolation performed with the bipolar radiofrequency clamp and excision or exclusion of the left atrial appendage. Most patients had connecting lesions between the right and left pulmonary veins and between the left atrial appendage and the left pulmonary veins. Novel statistical methods were used to create a plot of the prevalence of AF versus time after surgery. RESULTS: Mean time required for AF ablation was 17+/-4 minutes (range, 9-28 minutes). All patients left the operating room with sinus rhythm or with atrial or atrioventricular pacing for an underlying nodal rhythm. Perioperative AF was common, affecting 64% of patients. At discharge, 33% of patients were in AF or atrial flutter. By 3 months postoperatively, the predicted prevalence of AF or atrial flutter was 15%. There were no device-related complications. CONCLUSIONS: Bipolar radiofrequency facilitates rapid and safe AF ablation in patients with mitral valve disease. Perioperative AF is common and should be treated aggressively. By 3 months postoperatively, 85% of patients are free of AF or atrial flutter. Continued follow-up is necessary to document late results of this strategy.

Absorptiometry, Photon↗