Biventricular implantable cardioverter-defibrillator device placement in patients with hostile tricuspid valve anatomy: two case reports and review of the literature.

AIMS: Right ventricular (RV) lead placement can be contraindicated in patients after tricuspid valve (TV) surgery. Placement of the implantable cardiac-defibrillator (ICD) lead in the middle cardiac vein (MCV) can be a viable option in these patients who have an indication for biventricular (BiV) ICD. We aim to describe the case of two patients with MCV lead placement and provide a comprehensive review of patients with complex TV pathology and indications for RV lead placement. METHODS AND RESULTS: We describe the cases of two patients with TV pathology unsuitable for the standard transvenous or surgical RV lead placement and undergoing BiV ICD implantation. Their characteristics, procedure, and outcomes are summarized. The BiV ICD was successfully placed with the RV lead positioned in the MCV in both patients. The procedures had no complications and were well-tolerated. On follow-up, both patients had appropriate tachytherapy with no readmissions for heart failure or worsening of cardiac function. CONCLUSION: Right ventricular lead placement of BiV ICD in the MCV can be an excellent alternative in patients with significant TV pathology and poor surgical candidacy.

Atrial fibrillation and electrophysiology in transgenic mice with cardiac-restricted overexpression of FKBP12.

Cardiomyocyte-restricted overexpression of FK506-binding protein 12 transgenic (αMyHC-FKBP12) mice develop spontaneous atrial fibrillation (AF). The aim of the present study is to explore the mechanisms underlying the occurrence of AF in αMyHC-FKBP12 mice. Spontaneous AF was documented by telemetry in vivo and Langendorff-perfused hearts of αMyHC-FKBP12 and littermate control mice in vitro. Atrial conduction velocity was evaluated by optical mapping. The patch-clamp technique was applied to determine the potentially altered electrophysiology in atrial myocytes. Channel protein expression levels were evaluated by Western blot analyses. Spontaneous AF was recorded in four of seven αMyHC-FKBP12 mice but in none of eight nontransgenic (NTG) controls. Atrial conduction velocity was significantly reduced in αMyHC-FKBP12 hearts compared with NTG hearts. Interestingly, the mean action potential duration at 50% but not 90% was significantly prolonged in αMyHC-FKBP12 atrial myocytes compared with their NTG counterparts. Consistent with decreased conduction velocity, average peak Na+ current ( INa) density was dramatically reduced and the INa inactivation curve was shifted by approximately +7 mV in αMyHC-FKBP12 atrial myocytes, whereas the activation and recovery curves were unaltered. The Nav1.5 expression level was significantly reduced in αMyHC-FKBP12 atria. Furthermore, we found increases in atrial Cav1.2 protein levels and peak L-type Ca2+ current density and increased levels of fibrosis in αMyHC-FKBP12 atria. In summary, cardiomyocyte-restricted overexpression of FKBP12 reduces the atrial Nav1.5 expression level and mean peak INa, which is associated with increased peak L-type Ca2+ current and interstitial fibrosis in atria. The combined electrophysiological and structural changes facilitated the development of local conduction block and altered action potential duration and spontaneous AF. NEW & NOTEWORTHY This study addresses a long-standing riddle regarding the role of FK506-binding protein 12 in cardiac physiology. The work provides further evidence that FK506-binding protein 12 is a critical component for regulating voltage-gated sodium current and in so doing has an important role in arrhythmogenic physiology, such as atrial fibrillation.

Perioperative risk predictors of cardiac outcomes in patients undergoing liver transplantation surgery.

BACKGROUND: Cardiac risk assessment for perioperative outcomes of liver transplantation patients is limited. We examined the outcomes of an older intermediate-cardiac-risk group of patients undergoing liver transplantation surgery. METHODS AND RESULTS: Patients who had liver transplantation surgery between 2001 and 2005 were studied. The 3 outcomes analyzed were nonfatal myocardial infarction, death, and either outcome within the first 30 days after the liver transplantation surgery. Of 403 patients (mean age, 52+/-9 years; 67% male), 106 (26%) were diabetic, 84 (21%) were hypertensive, and 173 (43%) had a history of smoking. There were 48 total events (12%), 25 myocardial infarctions (7%), and 38 deaths (9%) recorded during the perioperative period. From the final multivariate model, history of coronary artery disease, prior stroke, and postoperative sepsis predicted greater risk (P=0.014; odds ratio [OR], 4.0; 95% confidence interval [CI], 1.3 to 11.8; P=0.025; OR, 6.6; 95% CI, 1.3 to 33.8; and P<0.001; OR, 7.5; 95% CI, 3.3 to 17.1, respectively). Use of perioperative beta-blockers was protective (P=0.004; OR, 0.20; 95% CI, 0.1 to 0.6) for combined cardiac outcomes. For the outcome of death on multivariate analysis, postoperative sepsis and increased interventricular septal thickness predicted risk (P<0.001; OR, 8.6; 95% CI, 3.5 to 20.9; and P=0.027; OR, 2.8; 95% CI, 1.1 to 7.2, respectively), whereas the use of perioperative beta-blockers was again protective (P=0.012; OR, 0.07; 95% CI, 0.01 to 0.56). CONCLUSIONS: In our study of cardiac risk assessment for liver transplantation surgery, history of stroke, coronary artery disease, postoperative sepsis, and increased interventricular septal thickness were markers of adverse perioperative cardiac outcomes, whereas use of perioperative beta-blockers was significantly protective.

Fragmented QRS complexes on 12-lead ECG: a marker of cardiac sarcoidosis as detected by gadolinium cardiac magnetic resonance imaging.

BACKGROUND: Fragmented QRS complexes (fQRS) on a 12-lead ECG are a marker of myocardial scar in patients with coronary artery disease. Cardiac sarcoidosis is also associated with myocardial granuloma formation and scarring. We evaluated the significance of fQRS on a 12-lead ECG compared to Gadolinium-delayed enhancement images (GDE) in cardiac magnetic resonance imaging (CMR). METHOD AND RESULTS: The ECGs of patients (n = 17, mean age: 52 +/- 11 years, male: 53%) with established diagnosis of sarcoidosis who underwent a CMR for evaluation of cardiac involvement were studied. ECG abnormalities included bundle branch block, Q wave, and fQRS. fQRS, Q wave, and bundle branch block were present in 9 (53%), 1 (6%), and 4 (24%) patients, respectively. The sensitivity and specificity of fQRS for detecting abnormal GDE were 100% and 80%, respectively. Sensitivity and specificity of Q waves were 11% and 100%, respectively. CONCLUSIONS: fQRS on a 12-lead ECG in patients with suspected cardiac sarcoidosis are associated with cardiac involvement as detected by GDE on CMR.

Prevalence and Prognostic Value of Right Ventricular Systolic Dysfunction in Patients With Constrictive Pericarditis Who Underwent Pericardiectomy.

Impaired right ventricular systolic function (RVSF) may complicate the treatment of constrictive pericarditis (CP) by pericardiectomy, which is a procedure that remains with significant morbidity and mortality. We evaluated RVSF in patients with CP who underwent pericardiectomy to determine the prognostic value of RVSF. RVSF was assessed by measuring Tricuspid Annular Plane Systolic Excursion (TAPSE) in 35 patients (mean age 52 ± 15.4 years) who underwent pericardiectomy. Thirty-one patients (88.6%) had reduced RVSF (TAPSE ≤1.8 cm). Eight patients (23%) had postoperative events (heart failure 3 and hospital mortality 5). Logistic regression showed that concomitant coronary artery bypass grafting (CABG) (p = 0.052), left ventricular ejection fraction (p = 0.059), left atrial diameter (p = 0.028), and TAPSE (p = 0.016) were borderline or significant univariate predictors of events. TAPSE (p = 0.018, odds ratio = 0.605 [0.40 to 0.92]) and CABG (p = 0.033, odds ratio = 20 [1.26 to 315]) were independent predictors of events on multivariate analysis. Stepwise analysis showed that TAPSE provided incremental prognostic value (p = 0.029, chi-square increase 11.6 to 16.3) to the combination of CABG, ejection fraction, and left atrial diameter. Receiver-operating characteristic curve analysis showed an area under the curve of 0.815 for TAPSE. TAPSE of 1.38 cm had a sensitivity of 88% and specificity of 67% for identifying patients with events. TAPSE was also inversely related to the length of hospital stay after pericardiectomy (p = 0.02, R = -0.424). Hence, our study showed that RVSF is frequently reduced in patients with CP who underwent pericardiectomy. In conclusion, TAPSE is an independent predictor of events and provides incremental prognostic value to other clinical and echocardiographic variables.

Coupling interval variability differentiates ventricular ectopic complexes arising in the aortic sinus of valsalva and great cardiac vein from other sources: mechanistic and arrhythmic risk implications.

OBJECTIVES: The objective of this study was to determine whether premature ventricular contractions (PVCs) arising from the aortic sinuses of Valsalva (SOV) and great cardiac vein (GCV) have coupling interval (CI) characteristics that differentiate them from other ectopic foci. BACKGROUND: PVCs occur at relatively fixed CI from the preceding normal QRS complex in most patients. However, we observed patients with PVCs originating in unusual areas (SOV and GCV) in whom the PVC CI was highly variable. We hypothesized that PVCs from these areas occur seemingly randomly because of the lack of electrotonic effects of the surrounding myocardium. METHODS: Seventy-three consecutive patients referred for PVC ablation were assessed. Twelve consecutive PVC CIs were recorded. The ΔCI (maximum - minimum CI) was measured. RESULTS: We studied 73 patients (age 50 ± 16 years, 47% male). The PVC origin was right ventricular (RV) in 29 (40%), left ventricular (LV) in 17 (23%), SOV in 21 (29%), and GCV in 6 (8%). There was a significant difference between the mean ΔCI of RV/LV PVCs compared with SOV/GCV PVCs (33 ± 15 ms vs. 116 ± 52 ms, p < 0.0001). A ΔCI of >60 ms demonstrated a sensitivity of 89%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 94%. Cardiac events were more common in the SOV/GCV group versus the RV/LV group (7 of 27 [26%] vs. 2 of 46 [4%], p < 0.02). CONCLUSIONS: ΔCI is more pronounced in PVCs originating from the SOV or GCV. A ΔCI of 60 ms helps discriminate the origin of PVCs before diagnostic electrophysiological study and may be associated with increased frequency of cardiac events.

Reduced right ventricular systolic function in constrictive pericarditis indicates myocardial involvement and persistent right ventricular dysfunction and symptoms after pericardiectomy.

We report four cases of patients with documented constrictive pericarditis who had evidence of reduced right ventricular (RV) systolic function. Assessment of RV systolic function was performed by pulsed tissue Doppler sampling of basal RV free wall velocity at the level of the tricuspid annulus in the four-chamber view. Velocity values and time velocity integral calculated from the velocity envelope were compared with values from controls. All four patients had evidence of epicardial RV injury at the time of pericardiectomy and persistent symptoms and RV systolic dysfunction after pericardiectomy.