Single-Centre Experience of Surgical Myectomy for Hypertrophic Obstructive Cardiomyopathy.

BACKGROUND: Septal myectomy is the gold standard treatment for hypertrophic obstructive cardiomyopathy. This study aimed to evaluate the results from patients with hypertrophic cardiomyopathy who had undergone septal myectomy. METHODS: Data were analysed that has been prospectively collected over 7 years from 345 patients with hypertrophic cardiomyopathy who underwent septal myectomy at Meshalkin National Medical Research Center. RESULTS: Six (6) patients (1.7%) died within 30 days of surgery. The mean (standard deviation, SD) resting left ventricular outflow tract gradients reduced from 83.4 (24.2) mmHg preoperatively to 16.2 (8.5) mmHg at discharge (p < 0.001). Of the 345 patients, 329 (95.4%) attended the most recent follow-up assessments, and of these, 254 (77.2%) were categorised as New York Heart Association (NYHA) class I, 64 (19.5%) class II, and 11 (3.3%) class III. The mean overall long-term survival rate after septal myectomy was 95.7% (SD 1.7%) (95% CI, 90.0-97.9). This did not differ from the age-matched and gender-matched general population (log-rank, p = 0.109). At the last follow-up assessments, six of 67 patients who had undergone concomitant Cox-Maze IV procedures had late atrial tachyarrhythmia recurrences. A preoperative short-axis view of left atrial diameter of 57.5 mm (hazard ratio, 1.30 (95% CI, 1.03-1.65), p < 0.001) predicted late atrial tachyarrhythmias (p < 0.002). CONCLUSIONS: At this hypertrophic cardiomyopathy centre, septal myectomy is associated with low operative and early mortality rates (<2%), a low risk of early adverse events, and acceptable intermediate-term clinical and haemodynamic results.

History and Current Status of Cardiac Anesthesiology in Russia.

Anesthesiology, the branch of medicine concerning anesthesia and management of the vital functions of patients undergoing surgery, has played an important role in the development of cardiac surgery. In the middle of the last century, medical professionals had little experience in the treatment of congenital and acquired heart diseases. Progress of cardiac anesthesiology in Russia, as well as in countries across the globe, was due to requests to increase the safety of surgical procedures and to improve survival rates for the increasing number of patients with complex heart diseases. The development of cardiac surgery and anesthesiology in Russia evolved in 2 directions simultaneously in the mid-1950s. Some surgeons widely accepted the use of perfusionless hypothermia (hypothermia caused by surface cooling without perfusion); others were in favor of cardiopulmonary bypass technology. This review focuses on major historic milestones of cardiac anesthesiology in Russia, including its current status and the major problems it faces today.

Hypothermic versus normothermic cardiopulmonary bypass in patients with valvular heart disease.

OBJECTIVE: The aim of this study was to test the hypothesis that normothermic cardiopulmonary bypass (CPB) is as effective as hypothermic CPB in terms of cardiac protection (cTnI level) and outcome in patients with valvular heart disease. DESIGN: Prospective randomized study. SETTING: A tertiary cardiothoracic referral center. PARTICIPANTS: 140 patients who had valvular heart disease, with/without coronary artery disease, surgically treated under CPB. INTERVENTIONS: The patients were allocated randomly to undergo either hypothermic (temperature [T], 31 °C-32 °C) or normothermic CPB (T>36 °C). MEASUREMENTS AND MAIN RESULTS: The primary endpoint was the dynamics of troponin I. The secondary endpoints were ventilation time, the need for inotropic support, intensive care unit (ICU) and hospital stay durations, complications, and mortality. There were no significant intergroup differences in dynamics of troponin I. Ventilation time was significantly lower in the hypothermic group (6 (5-9) and 8 (5-12); p = 0.01). CONCLUSIONS: Normothermic CPB in patients with valvular heart disease was as effective as hypothermic perfusion in terms of myocardial protection after the surgery assessed by cTnI release. The short ventilation duration in patients who underwent hypothermic CPB needs to be confirmed in a future investigation.

Randomized trial of fish oil infusion to prevent atrial fibrillation after cardiac surgery: data from an implantable continuous cardiac monitor.

OBJECTIVE: To test the hypothesis that perioperative OMEGA-3 polyunsaturated fatty acid infusion would reduce the incidence of postoperative atrial fibrillation in patients after coronary artery bypass grafting as assessed by an implantable continuous cardiac monitor. DESIGN: Prospective, randomized, double-blind, placebo-controlled study. SETTING: Tertiary cardiothoracic referral center. PARTICIPANTS: Thirty-nine patients with coronary artery disease who underwent surgery with cardiopulmonary bypass. INTERVENTIONS: Patients were assigned randomly to receive either OMEGA-3 polyunsaturated fatty acids (200 mg/kg/day starting before anesthesia induction for 24 hours followed by 100 mg/kg/day for 7 days) or placebo. The primary outcome was freedom from atrial fibrillation at 2-year follow-up. Reveal(®) cardiac monitor was implanted subcutaneously in all patients. Data from the cardiac monitor were collected on the 10th day and 3, 6, 12, and 24 months postoperatively. MEASUREMENT AND MAIN RESULTS: Postoperative atrial fibrillation developed in 4 (19%) patients in the control group and in 5 (27.8%) patients in the study group at 10-day follow-up (p = 0.88). At 2-year follow-up, 5 (27.8%) patients in the control group and 6 (35.3%) patients in the study group had atrial fibrillation (p = 0.9). Atrial fibrillation duration predicted risk of cardiovascular hospitalization at the 2-year follow-up (regression coefficient estimate = 0.24, standard error 0.02, p<0.0001; R(2) = 0.74). CONCLUSIONS: Infusion of OMEGA-3 polyunsaturated fatty acids failed to prevent the occurrence of atrial fibrillation in 2 years after coronary artery bypass grafting surgery. The cumulative atrial fibrillation duration registered by the continuous cardiac monitor at the 2-year follow-up was a significant predictor of an adverse outcome.

Mortality prediction in patients with dialysis-dependent acute kidney injury after cardiac surgery with cardiopulmonary bypass.

BACKGROUND: To build a predictive model for patients with dialysis-dependent acute kidney injury (AKI-D) after cardiac surgery with the cardiopulmonary bypass (CPB), according to disease severity. METHODS: A single-centre, retrospective cohort study was performed to determine the demographic and clinical parameters (including the specific factor, CPB duration) for risk of poor outcome in patients requiring RRT after cardiac surgery with CPB. A new model was built for mortality prediction in these patients on the basis of the identified risk factors and Sequential Organ Failure Assessment score. RESULTS: The newly developed model showed good discriminatory ability for predicting death in patients with AKI-D after cardiac surgery with CPB. The area under the receiver-operating characteristic (ROC) curve for the score was 0.892 (95% confidence interval, 0.852-0.925). We also determined the criterion for the choice of RRT modality by applying this model. On applying the new model in intermittent haemodialysis patients, a score of ≤3.2 was found safe for selecting the RRT modality. CONCLUSIONS: The new scoring system was valid and accurate in predicting death for AKI-D patients after open-heart surgery. This system and value for choice of RRT were determined for guidance only, to facilitate decision-making in difficult situations.

Evaluation of nutritional screening tools among patients scheduled for heart valve surgery.

BACKGROUND AND AIM OF THE STUDY: The study aim was to detect the most sensitive nutritional screening tool and to assess its prognostic value with regards to an adverse clinical course in patients with heart valve disease undergoing cardiopulmonary bypass (CPB). METHODS: This prospective cohort study included 441 adult patients who were screened using four nutritional screening tools: Nutritional Risk Screening 2002 (NRS-2002); Malnutrition Universal Screening Tool (MUST); Mini Nutritional Assessment (MNA); and Short Nutritional Assessment Questionnaire (SNAQ). Nutritional assessment was performed using a Subjective Global Assessment (SGA). In-hospital mortality, postoperative complications, and duration of hospital stay were each analyzed. RESULTS: With regards to the detection of malnutrition, the sensitivities of MUST, SNAQ, MNA and NRS-2002 were 100%, 92%, 84.6% and 43.6%, respectively. Malnutrition identified by MUST and MNA were associated with postoperative complications (OR 1.63, p = 0.033 and OR 1.6, p = 0.035) and prolonged hospitalization (OR 1.57, p = 0.048 and OR 1.7, p = 0.02). According to multivariate logistic regression analysis, along with well-known age and duration of CPB, malnutrition identified by MUST and MNA was associated with a risk of development of complications (OR 1.6, p = 0.049 and OR 1.6, p = 0.04, respectively). The sensitivities of SNAQ, MUST, NRS-2002 and MNA with regards to postoperative complications were 26.8%, 28.8%, 10%, and 31.6%, respectively. CONCLUSION: The MUST tool is preferable with regards to the detection of malnutrition. Both, MUST and MNA independently predicted postoperative complications. SNAQ and NRS-2002 proved insensitive with regards to the postoperative course among patients with heart valve disease who were scheduled for cardiothoracic surgery.

Hypertonic solution decreases extravascular lung water in cardiac patients undergoing cardiopulmonary bypass surgery.

OBJECTIVE: To test the hypothesis that the infusion of hypertonic solution would decrease extravascular lung water postoperatively and thus improve pulmonary function. DESIGN: Prospective, randomized, blinded trial. SETTING: Tertiary cardiothoracic referral center. PARTICIPANTS: Twenty-six patients with coronary artery disease who underwent surgery with cardiopulmonary bypass (CPB). INTERVENTIONS: Patients were allocated randomly to receive 4 mL/kg of 7.2% NaCl/hydroxyethyl starch, 200/0.5 (HSH group) or an equal volume of 0.9% NaCl (control group) for 30 minutes starting after anesthesia induction. The extravascular lung water index, hemodynamic and biochemical data, and the rate of complications were analyzed. MEASUREMENTS AND MAIN RESULTS: The extravascular lung water index was significantly lower (7 v 9.5 mL/kg) in the HSH group at the first postoperative day (p < 0.01). The index of arterial oxygenation efficiency was significantly higher at 5 minutes and 2 and 4 hours after cardiopulmonary bypass (CPB) in the HSH group (p < 0.05). The alveolar-arterial oxygen tension difference was significantly lower at 5 minutes and 2 and 4 hours after CPB in the HSH group (p < 0.01). The cardiac index was significantly higher at 5 minutes after infusion in the HSH group (p < 0.05). CONCLUSIONS: The infusion of HSH leads to significant decreases in the extravascular lung water index during and after cardiac surgery and is associated with better preservation of pulmonary function and transient increases in the cardiac index. Further trials are needed to clarify the clinical advantages of hypertonic solution administration in patients undergoing surgery with CPB.

Methylprednisolone use is associated with endothelial cell activation following cardiac surgery.

BACKGROUND: The objective of this study was to investigate the effect of the perioperative use of methylprednisolone in medium doses on markers of endothelial cell activation in patients with coronary artery disease undergoing cardiopulmonary bypass. METHODS: In this prospective, double-blinded, placebo-controlled, randomised study, 44 patients, undergoing a coronary artery bypass graft surgery received either methylprednisolone 20 mg/kg or a placebo intraoperatively after anaesthesia induction. The primary endpoint was endothelin-1, and secondary endpoints were E-selectin, interleukin (IL)-6 and IL-10, PaO(2)/FiO(2) coefficient, and microalbuminuria. RESULTS: Endothelin-1 was higher in the study group postoperatively at 10 min (p=0.0008), 2 h (p=0.02), 4 h (p=0.005), and 24 h (p=0.004). IL-6 was lower in the study group postoperatively at 2 h (p=0.03), 4 h (p=0.04), and 24 h (p<0.0001). IL-10 was higher in the study group postoperatively at 10 min (p<0.0001), 2 h (p=0.009), and 4 h (p=0.001). PaO(2)/FiO(2) was lower in the study group at 24 h after surgery (p=0.03). Microalbuminuria was similar in both groups. CONCLUSION: Despite an obvious anti-inflammatory effect, methylprednisolone causes endothelial cell activation in patients undergoing cardiopulmonary bypass.

Does glutamine promote benefits for patients with diabetes mellitus scheduled for cardiac surgery?

BACKGROUND: We hypothesised, that perioperative use of N(2)-L-alanyl-L-glutamine confers cardioprotection and improves insulin resistance in diabetic patients with coronary artery disease operated under cardiopulmonary bypass. METHODS: This double-blind, placebo-controlled, randomised study included 64 patients with diabetes mellitus type 2 who were scheduled for on-pump coronary artery bypass graft surgery. The protocol group (32 patients) and the control group (32 patients) glutamine (0.4 g/kg/day of 20% solution of N(2)-L-alanyl-L-glutamine ("Dipeptiven(®)" Fresenius Kabi, Germany)) and placebo (0.9% NaCl), respectively. Perioperative concentration of troponin I in plasma was considered as the primary end-point. Whereas the secondary end-points were insulin resistance, insulin sensitivity, ß-cell function, blood glucose, plasma triglycerides and free fatty acids concentrations. Insulin resistance, insulin sensitivity and ß-cell function were measured using HOMA equation. Thermodilution method was used to measure haemodynamics in all the patients. RESULTS: No differences have been found in perioperative dynamics of troponin I, insulin resistance, insulin sensitivity, ß-cell function, blood glucose, plasma triglycerides free fatty acids concentrations and haemodynamics. CONCLUSION: Our results have failed to confirm the cardioprotective properties and modulatory effect on perioperative insulin resistance that are thought to be attributable to parenteral glutamine administration in dose 0.4 g/kg/day among cardiac patients with DM operated on under CPB.

Levosimendan versus an intra-aortic balloon pump in high-risk cardiac patients.

OBJECTIVE: To test the hypothesis that levosimendan is more effective than intra-aortic balloon pump (IABP) support in cardiac surgical patients with low left ventricular ejection fraction to decrease cardiac troponin I levels (primary endpoint) and improve hemodynamics. DESIGN: Prospective randomized trial. SETTING: Tertiary cardiothoracic referral center. PARTICIPANTS: Ninety patients with coronary artery disease and left ventricular ejection fraction <35% who underwent surgery with cardiopulmonary bypass. INTERVENTION: Patients were assigned randomly to 1 of 3 groups. Group A received a prophylactic IABP one day before surgery. Group B received a prophylactic IABP one day before surgery and a levosimendan infusion at a dose of 0.1 µg/kg/min with an initial bolus (12 µg/kg for 10 minutes) after anesthesia induction. Group C received a levosimendan infusion at a dose of 0.1 µg/kg/min with an initial bolus (12 µg/kg for 10 minutes) after anesthesia induction. Hemodynamic and biochemical data and rate of complications were analyzed. MEASUREMENTS AND MAIN RESULTS: The cardiac troponin I level in group C 6 hours after surgery was lower than in group A (p = 0.048). The cardiac index in group A was significantly lower than in groups B and C. The intensive care unit stay was significantly shorter in group C than in groups A and B (p = 0.001). The need for inotropic support, the rate of complications, and mortality among groups did not differ. CONCLUSIONS: The infusion of levosimendan after anesthesia induction in cardiac surgical patients contributes to lower cardiac troponin I levels and improved hemodynamics compared with a preoperative IABP.

Preoperative total lymphocyte count in peripheral blood as a predictor of poor outcome in adult cardiac surgery.

OBJECTIVE: The aim of this study was to investigate the prognostic value of the preoperative total lymphocyte count in peripheral blood as a predictor of postoperative complications and mortality in cardiac surgery. DESIGN: A retrospective, observational study. SETTING: The Novosibirsk State Research Institute of Circulation Pathology (single institution). PARTICIPANTS: All adults undergoing primary cardiopulmonary bypass in 2009. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The cohort size was 1,368 patients operated upon with cardiopulmonary bypass. Patient characteristics, hospital mortality, postoperative complications, ventilation time, intensive care unit, and hospital stay were analyzed. A preoperative total lymphocyte count <1,500 cells/µL was associated with significantly higher mortality by univariate (p < 0.0001) and multivariate (p < 0.044) analyses. A low preoperative total lymphocyte count was associated with more frequent inotropic support (p < 0.001); postoperative heart arrhythmia (p < 0.001); dialysis-dependent acute renal failure (p < 0.001); and a prolonged ventilation time (p = 0.001), intensive care unit stay (p < 0.001), and hospital stay (p = 0.007). CONCLUSIONS: A low preoperative total lymphocyte count in peripheral blood is a useful prognostic criterion for the evaluation of a complicated postoperative period in cardiac patients operated under cardiopulmonary bypass.

Glutamine is cardioprotective in patients with ischemic heart disease following cardiopulmonary bypass.

BACKGROUND: The aim of the present study was to investigate the cardioprotective effects of the perioperative use of N(2)-L-alanyl-L-glutamine (GLN) in patients with ischemic heart disease (IHD) who undergo their operations under cardiopulmonary bypass (CPB). METHODS: This double-blind, placebo-controlled, randomized study included 50 patients who underwent cardiac surgery with CPB. Exclusion criteria were a left ventricular ejection fraction <50%, diabetes mellitus, <3 months since the onset of myocardial infarction, and emergency surgery. Patients in the study group (n = 25) received 0.4 g/kg GLN (Dipeptiven, 20% solution) per day. Patients in the control group (n = 25) were administered a placebo (0.9% NaCl). The primary end point was the dynamics of troponin I at the following stages: (1) prior to anesthesia, (2) 30 minutes after CPB, (3) 6 hours after CPB, (4) 24 hours after surgery, and (5) 48 hours after surgery. Secondary end points included measurements of hemodynamics with a Swan-Ganz catheter. RESULTS: On the first postoperative day after the surgery, the median troponin I level was significantly lower in the study group than in the placebo group: 1.280 ng/mL (interquartile range [IQR], 0.840-2.230 ng/mL) versus 2.410 ng/mL (IQR, 1.060-6.600 ng/mL) (P = .035). At 4 hours after cardiopulmonary bypass (CPB), the median cardiac index was higher in the patients in the study group: 2.58 L/min per m2 (IQR, 2.34-2.91 L/min per m2) versus 2.03 L/min per m2 (IQR, 1.76-2.32 L/min per m2) (P = .002). The median stroke index also was higher in the patients who received GLN: 32.8 mL/m2 (IQR, 27.8-36.0 mL/m2) versus 26.1 mL/m2 (IQR, 22.6-31.8 mL/m2) (P = .023). The median systemic vascular resistance index was significantly lower in the study group than in the placebo group: 1942 dyn·s/cm5 per m2 (IQR, 1828-2209 dyn·s/cm5 per m2) versus 2456 dyn·s/cm5 per m2 (IQR, 2400-3265 dyn·s/cm5 per m2) (P = .001). CONCLUSION: Perioperative administration of GLN during the first 24 hours has cardioprotective effects in IHD patients following CPB. This technique enhances the troponin concentration at 24 hours after surgery and is associated with improved myocardial function.

Diepoxy- Versus Glutaraldehyde-Treated Xenografts: Outcomes of Right Ventricular Outflow Tract Reconstruction in Children.

BACKGROUND: Xenografts used for right ventricular outflow tract (RVOT) reconstruction are typically treated with glutaraldehyde. However, potential benefit of epoxy treatment was demonstrated in experimental studies. We aimed to compare diepoxy-treated bovine pericardial valved conduits (DE-PVCs) and glutaraldehyde-treated bovine pericardial valved conduits (GA-PVCs) for RVOT reconstruction in pediatric patients. METHODS: Between 2002 and 2017, 117 patients underwent RVOT reconstruction with PVC in single center: DE-PVC group, n = 39; and GA-PVC group, n = 78. After performing propensity score analysis (1:1) for the entire sample, 29 patients from the DE-PVC group were matched with 29 patients from the GA-PVC group. RESULTS: There were no conduit-related deaths. In the DE-PVC group, the freedom from conduit failure was 90.9% at four years and 54.3% at eight years postoperatively. In the GA-PVC group, it was 46.3% and 33.1%, respectively. The difference was significant (P = .037). Conduit failure was typically caused by stenosis in both groups. In the DE-PVC group, the main cause of stenosis was xenograft calcification (27.6%); while in the GA-PVC group, it was mostly due to neointimal proliferation (25.0%) and, less often, calcification (14.3%). Conduit thrombosis was the cause of replacement in 6.9% of patients from the GA-PVC group. CONCLUSIONS: Diepoxy-treated bovine pericardial valved conduit is a suitable alternative to GA-PVC for RVOT reconstruction in pediatric patients. Diepoxy-treated bovine pericardial valved conduits may be less prone to conduit failure and more resistant to neointimal proliferation and conduit thrombosis than GA-PVCs.

General Study and Gene Expression Profiling of Endotheliocytes Cultivated on Electrospun Materials.

Endothelization of the luminal surface of vascular grafts is required for their long-term functioning. Here, we have cultivated human endothelial cells (HUVEC) on different 3D matrices to assess cell proliferation, gene expression and select the best substrate for endothelization. 3D matrices were produced by electrospinning from solutions of poly(D,L-lactide-co-glycolide) (PLGA), polycaprolactone (PCL), and blends of PCL with gelatin (Gl) in hexafluoroisopropanol. Structure and surface properties of 3D matrices were characterized by SEM, AFM, and sessile drop analysis. Cell adhesion, viability, and proliferation were studied by SEM, Alamar Blue staining, and 5-ethynyl-2'-deoxyuridine (EdU) assay. Gene expression profiling was done on an Illumina HiSeq 2500 platform. Obtained data indicated that 3D matrices produced from PCL with Gl and treated with glutaraldehyde provide the most suitable support for HUVEC adhesion and proliferation. Transcriptome sequencing has demonstrated a minimal difference of gene expression profile in HUVEC cultivated on the surface of these matrices as compared to tissue culture plastic, thus confirming these matrices as the best support for endothelization.

A left atrial versus a biatrial lesion set for persistent atrial fibrillation ablation during open heart surgery.

OBJECTIVES: To compare the outcomes of left atrial ablation and biatrial (BA) ablation in patients with persistent and long-standing persistent atrial fibrillation undergoing open heart surgery. METHODS: Between January 2007 and December 2016, 588 consecutive patients with either persistent (20.9%) or long-standing persistent atrial fibrillation (79.1%) were enrolled in this study. To reduce between-group differences, propensity score-matched groups (156 patients/group) were obtained, with similar preoperative and perioperative characteristics. RESULTS: The propensity score-matched left atrial and BA groups did not differ regarding 30-day mortality (1.9% vs 0.6%; P = 0.617), 5-year overall survival (93.5 ± 2.2% vs 92.8 ± 2.9%, P = 0.998) or survival free from thromboembolic events (97.1 ± 2.8% vs 96.2 ± 2.7%, P = 0.309). The BA lesion set was more beneficial in terms of freedom from atrial arrhythmia recurrence (85.3 ± 4.5% vs 91.9 ± 3.1%, P = 0.049; hazard ratio 3.26; 95% confidence interval 1.33-7.99), but it was associated with higher pacemaker implantation rate (3.8% vs 17.3%; P < 0.001) due to sinus node dysfunction. There was no significant between-group difference regarding the incidence of atrioventricular conduction disturbances (3.2% vs 7.0%, respectively; P = 0.211). CONCLUSIONS: The 2 lesion sets (left atrial and BA) are associated with similar 30-day mortality, survival rates, incidences of embolic events and atrioventricular conduction disturbances. In patients with persistent atrial fibrillation, concomitant surgical ablation with BA lesion set provided better freedom from atrial arrhythmia recurrence, but BA ablation was associated with a higher incidence of sinus node dysfunction and a higher rate of pacemaker implantation.

Concomitant ablation for atrial fibrillation during septal myectomy in patients with hypertrophic obstructive cardiomyopathy.

OBJECTIVE: The appearance of atrial fibrillation is associated with significant clinical deterioration in patients with obstructive hypertrophic cardiomyopathy; therefore, maintenance of sinus rhythm is desirable. Guidelines and most articles have reported the results of catheter ablation and pharmacologic atrial fibrillation treatment; nevertheless, data regarding concomitant procedures during septal myectomy are limited. The aim of this study was to assess the outcomes of concomitant atrial fibrillation treatment in patients with obstructive hypertrophic cardiomyopathy. METHODS: Between 2010 and 2013 in our clinic, 187 patients with obstructive hypertrophic cardiomyopathy underwent extended myectomy. In 45 cases, concomitant Cox-Maze IV procedure was performed; however, obstructive hypertrophic cardiomyopathy was the primary indication for surgery. Atrial fibrillation was paroxysmal in 26 patients (58%) and nonparoxysmal in 19 patients (42%). The mean age of patients was 52.8 ± 14.2 years (range, 22-74 years). Mean peak gradient was 90.7 ± 24.2 mm Hg, and interventricular septum thickness was 26.1 ± 4.3 mm. Mean atrial fibrillation duration was 17.3 ± 8.5 months. RESULTS: There were no early deaths. No procedure-related complications occurred with regard to ablation procedure. Complete atrioventricular block was achieved in 2 patients (4.0%). Mean crossclamping time was 61 ± 36 minutes. Peak left ventricular outflow tract gradient was 12.6 ± 5.5 mm Hg based on transesophageal echocardiography. The Maze IV procedure was used for ablation in all patients (radiofrequency ablation with bipolar clamp + cryolesion for mitral and tricuspid lines). Because of the atrial wall thickness (5-6 mm), applications were performed 8 to 10 times on each line. There were no cases of pacemaker implantation due to sinus node dysfunction. All patients were discharged in stable sinus rhythm. Mean follow-up was 23.7 ± 1.3 months. The rate of atrial fibrillation freedom was 100% (45 patients) at 6 months, 89% (40 patients) at 1 year, and 78% (35 patients) at 24 months. CONCLUSIONS: Concomitant ablation atrial fibrillation during septal myectomy in patients with obstructive hypertrophic cardiomyopathy is a safe and effective procedure and should be considered carefully in this patient group.