Ventricular Functional Analysis in Congenital Complete Heart Block Using Speckle Tracking: Left Ventricular Epicardial Compared to Right Ventricular Septal Pacing.

BACKGROUND: Chronic right ventricular (RV) apical pacing in patients with congenital complete atrioventricular block (CCAVB) is associated with left ventricle (LV) dyssynchrony and dysfunction. Hence, alternative pacing sites are advocated. The aim of this study was to compare LV function using STE in selected patients with LV epicardial pacing (LVEp) vs. RV transvenous pacing (RVSp). METHODS: This was a single-center, retrospective study in patients with CCAVB who underwent permanent pacemaker implant at age ≤ 18 years. Age- and gender-matched patients with a normal heart anatomy and function served as the control group. LV function was comprehensively assessed by conventional 2D Echocardiography and speckle-tracking echocardiography (STE). RESULTS: We included 24 patients in the pacemaker group [27.6% male, mean age of 17.1 at last follow-up, follow-up duration of 8.7 years, RVSp (n = 9; 62.5%)] compared to 48 matched healthy controls. Shortening fraction (SF) and ejection fraction (EF) were normal and similar between cases and controls. However, STE detected abnormal LV function in the pacemaker group compared to controls. The former demonstrated lower/abnormal, Peak Longitudinal Strain myocardial (PLS Myo) [- 12.0 ± 3.3 vs. - 18.1 ± 1.9, p < 0.001] and Peak Longitudinal Strain endocardial (PLS endo) [- 16.1 ± 4.1 vs. 1.7 ± 1.7, p < 0.001]. STE parameters of LV function were significantly more abnormal in LVEp vs. RVSp subgroup as demonstrated by lower values for PLS Myo (- 10.1 ± 3.2 vs. - 13.1 ± 2.9, p = 0.03) and PLS Endo (- 13.8 ± 4.4 vs. - 17.5 ± 3.3, p = 0.03). CONCLUSION: STE was more sensitive in detecting subtle differences in LV function relative to standard conventional 2D echocardiography (SF and EF) in selected patients with CCAVB and a permanent pacemaker. Furthermore, STE demonstrated that transvenous RV septal pacing was associated with better LV systolic function preservation than LV epicardial pacing for comparable post-implant intervals.

Segment Length in Cine Strain Analysis Predicts Cardiac Resynchronization Therapy Outcome Beyond Current Guidelines.

BACKGROUND: Patients with a class I recommendation for cardiac resynchronization therapy (CRT) are likely to benefit, but the effect of CRT in class II patients is more heterogeneous and additional selection parameters are needed in this group. The recently validated segment length in cine strain analysis of the septum (SLICE-ESSsep) measurement on cardiac magnetic resonance cine imaging predicts left ventricular functional recovery after CRT but its prognostic value is unknown. This study sought to evaluate the prognostic value of SLICE-ESSsep for clinical outcome after CRT. METHODS: Two hundred eighteen patients with a left bundle branch block or intraventricular conduction delay and a class I or class II indication for CRT who underwent preimplantation cardiovascular magnetic resonance examination were enrolled. SLICE-ESSsep was manually measured on standard cardiovascular magnetic resonance cine imaging. The primary combined end point was all-cause mortality, left ventricular assist device, or heart transplantation. Secondary end points were (1) appropriate implantable cardioverter defibrillator therapy and (2) heart failure hospitalization. RESULTS: Two-thirds (65%) of patients had a positive SLICE-ESSsep ≥0.9% (ie, systolic septal stretching). During a median follow-up of 3.8 years, 66 (30%) patients reached the primary end point. Patients with positive SLICE-ESSsep were at lower risk to reach the primary end point (hazard ratio 0.36; P<0.001) and heart failure hospitalization (hazard ratio 0.41; P=0.019), but not for implantable cardioverter defibrillator therapy (hazard ratio, 0.66; P=0.272). Clinical outcome of class II patients with a positive ESSsep was similar to those of class I patients (hazard ratio, 1.38 [95% CI, 0.66-2.88]; P=0.396). CONCLUSIONS: Strain assessment of the septum (SLICE-ESSsep) provides a prognostic measure for clinical outcome after CRT. Detection of a positive SLICE-ESSsep in patients with a class II indication predicts improved CRT outcome similar to those with a class I indication whereas SLICE-ESSsep negative patients have poor prognosis after CRT implantation.

Factors associated with implantable cardioverter defibrillators appropriate therapy in cardiac sarcoidosis: a meta-analysis.

BACKGROUND: Patients with cardiac sarcoidosis (CS) are at increased risk of atrioventricular blocks, ventricular arrhythmias, and sudden cardiac death. Objectives We aimed to investigate the characteristics associated with appropriate therapy in implantable cardiac defibrillator (ICD) -implanted CS patients. METHODS: We performed a PubMed and Web of Science search for studies reporting patients with CS who underwent an ICD implantation. The primary criterion was an appropriate therapy. RESULTS: We screened 705 studies, of which 5 were included in the final analysis. We conducted a meta-analysis including 464 patients (mean age 55 years, 282 males (60%)). The mean follow-up was 3.5 years. Among the 464 patients, 180 received an appropriate therapy (39%). Patients who received an appropriate therapy were younger (-3.33, 95% confidence interval (CI) -6.42 to -0.23, p=0.004), were more likely to be male (OR 2.06, 95% CI 1.37-3.09, p=0.0005), had a lower left ventricular ejection fraction (LVEF) (-10.5, 95% CI -18.23 to -2.78, p=0.008), had a higher rate of complete heart block (OR 2.19, 95% CI 1.20 to 3.99, p=0.01), and more frequently had ventricular pacing (OR 6.44 95% CI 2.57 to 16.16, p<0.0001). CONCLUSIONS: Appropriate ICD therapy during CS is associated with young age, male sex, low LVEF, history of complete heart block, and ventricular pacing. (Sarcoidosis Vasc Diffuse Lung Dis 2020; 37 (1): 17-23).

Leadless pacemaker use in a patient with a durable left ventricular assist device.

There is limited known safety and efficacy of leadless pacemaker device use in patients with durable left ventricular assist devices (LVADs). We present a case of a pacemaker-dependent LVAD patient with infection of permanent transvenous pacemaker who underwent successful implantation of Micra transcatheter pacing system (Medtronic).

Occurrence of complete heart block associated with acute renal infarction.

Complete heart block (CHB) and acute renal infarction (ARI) are both uncommon diseases and seldom encountered in the clinical practice. We describe a rare case of pre-existing left bundle branch block, presenting simultaneously with CHB and ARI. The possible mechanism depends on prior presence of either CHB or ARI. If ARI occurs first, severe pain and embolism may enhance the vagal tone resulting in decrease in the heart rate and transient intraventricular conduction interruption, which subsequently causes CHB. The opposite scenario, CHB preceding ARI, is also possible. CHB can be physiologic and transient, with higher risk of development in the circumstance of pre-existing conduction system disturbances. Patients with CHB are predisposed to formation of thrombi and thromboemboli, giving rise to ARI. In conclusion, awareness and timely identification of the clinical manifestations of these two diseases may facilitate early diagnosis and prompt management.

Leadless Pacemaker Implant After Heart Transplant.

Conduction abnormalities are known to occur after heart transplantation. In some cases, a permanent pacemaker is required. Conventional transvenous pacemakers can result in several complications, mainly related to the leads and device pocket. Leadless pacemaker technology was developed to overcome these issues. We report what we believe is the first US case of a leadless pacemaker implant (specifically in a heart transplant recipient) with the longest reported duration of follow-up.

A New Technique Using 4DCT Scans to Create Custom Cardiac Blocks for Left-Sided Breast Cancer Treatments.

PURPOSE: For patients who receive treatment for left breast cancer, cardiac toxicity increases with increased radiation dose to the heart. A new method was developed using 4-dimensional computed tomography (CT) scans to improve custom cardiac blocks to minimize heart dose. METHODS AND MATERIALS: Four-dimensional CT scans were acquired, and a maximum intensity projection (MIP) heart was contoured for 20 patients. Custom heart blocks were created to fully block the MIP heart volume. A heart block based on the standard free-breathing (FB) CT image was retrospectively created. Differences in heart block sizes were compared. Differences in heart block areas and dose statistics were analyzed. RESULTS: In all 20 cases, the heart block created using the 4-dimensional scan had a larger area than the corresponding FB block. The mean increase in multileaf collimator coverage was 3.9 mm (range, 0.5-20.1 mm). The mean increase in the area of the heart block was 2.58 cm2 (range, 0.22-6.65 cm2). The dose-volume histogram showed that the MIP heart received 17.8 cGy (range, 0.02-70.3 cGy) more than the FB heart on average. Replanning with an FB heart block showed that the mean dose to the MIP heart increased by 16.2 cGy (range, 1.8-44.8 cGy) compared with the FB heart dose. CONCLUSIONS: Four-dimensional heart blocks accounting for intrinsic respiratory motion and cardiac motion were greater in size than FB heart blocks. These larger blocks resulted from the larger contour created from the MIP image and blocked more dose to the heart. This technique for improving custom heart blocks can be easily implemented with 4DCT machine capabilities that are currently available in clinical practice.

A case of esophagogastroduodenoscopy induced Takotsubo cardiomyopathy with complete heart block.

Takotsubo cardiomyopathy (TC) describes a reversible left ventricular dysfunction characterized by apical ballooning and basal hyperkinesis, commonly triggered by emotional or physical distress. TC associated with an esophagogastroduodenoscopy (EGD) has rarely been reported. We report a case of TC with complete heart block (CHB) in a patient receiving an EGD, who had no underlying cardiac disease, had previously tolerated both local and general anesthesia, and who had previously undergone similar endoscopic procedures without complications. The concurrence of both TC and CHB is unique in this case pertaining to a patient with no significant risk factors. The incidence, mechanism and prognosis of TC-associated arrhythmias are also reviewed.

Complete heart block in young adult with acute rheumatic fever.

Acute Rheumatic fever (ARF) is commonly associated with ECG abnormalities particularly atrioventricular block. However, third degree atrioventricular block or complete heart block is a rare manifestation. Most cases occurred in children. We reported a 25 year old man who developed complete heart block during an acute episode of ARF. He presented to hospital with five days history of fever, malaise and migrating arthralgia, followed by pleuritic chest pain. One day after admission his electrocardiogram (ECG) revealed complete heart block. Transthoracic echocardiography showed good left ventricular function with thickened, mild mitral regurgitation with minimal pericardial effusion. ASOT titer was positive with elevated white blood count and acute phase reactant. A temporary pacemaker was inserted in view of symptomatic bradycardia. The complete heart block resolved after medical therapy. He was successfully treated with penicillin, steroid and aspirin. He was discharged well with oral penicillin. The rarity of this presentation is highlighted.