FDG-PET/CT and rest myocardial perfusion imaging to predict high-degree atrioventricular block recovery in cardiac sarcoidosis.

BACKGROUNDS: High-degree atrioventricular block (AVB) recovery in CS has been shown to be highly variable despite immunosuppressive treatment, with no reliable tool available to predict odds of reversibility. This study sought to evaluate the potential of combined fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) and resting myocardial perfusion imaging (rMPI) to predict reversibility of newly diagnosed high-grade AVB in cardiac sarcoidosis (CS). METHODS: We performed a single-center, retrospective analysis of patients with CS presenting with high-grade AVB who underwent combined FDG-PET/CT and rMPI. The 2016 JCS and the 2014 HRS diagnostic criteria were used for the diagnosis of CS. Patients with a history of coronary artery disease or prior immunosuppressive treatment were excluded. Patients were divided into AVB recovery and non-recovery subgroups. CS disease staging was based on FDG-PET and rMPI findings: (Stage 0) normal FDG-PET and rMPI (Stage 1) positive FDG-PET and normal rMPI (Stage 2) positive FDG-PET with perfusion deficits on rMPI (Stage 3) normal FDG-PET with perfusion deficits on rMPI. RESULTS: Twenty-seven patients, including 13 demonstrating AVB recovery, were identified. Eleven out of fourteen (78.6%) patients presenting with stage 1 CS demonstrated AVB recovery. Stage 1 CS was significantly more present in the recovery group compared to the non-recovery group (84.6% vs 21.4%, P = .002). Eleven presented with stage 2 CS, with only 2 (18.2%) recovering AV nodal conduction. Stage 2 CS presented more frequently in the non-recovery group (64.3% vs 15.4%, P = .020). CONCLUSIONS: Combined FDG-PET and rMPI employed to stage CS disease presenting with high-degree AVB appears to have good performance for predicting likelihood of recovery.

Use of Polynomial Reference Ranges for Atrioventricular Intervals Assessed by Fetal Echocardiography in Anti-Ro/SSA Antibody-Positive Pregnancies to Exclude Fetal Heart Blocks: A Pilot Study.

INTRODUCTION: Maternal anti-Ro/SSA antibodies can cause fetal atrioventricular blocks (AVB). This pilot study aims to apply previously published echocardiographic reference ranges of the fetal atrioventricular (AV) intervals in the setting of anti-Ro/SSA antibody-positive pregnancies in order to exclude a 1° AVB. MATERIALS AND METHODS: Between January 2018 and September 2022, we included all women with known anti-Ro/SSA antibodies followed up at the prenatal ultrasound department of the University Hospital of Bern. AV intervals were serially measured by two previously reported methods and plotted against previously created reference ranges. RESULTS: We included 23 pregnancies from 17 anti-Ro/SSA antibody-positive women with connective tissue diseases. 443 AV interval measurements were recorded between 16+3 and 38+4 weeks of gestation. 14 (3.2%) AV-intervals measured >150 ms, none measured >170 ms and 8 (1.8%) were found to be >95th percentile. In none of the pregnancies, serial AV-prolongations were noted. The postnatal electrocardiograms demonstrated normal sinus rhythm without AVB in all children. CONCLUSION: AV intervals of pregnancies followed up for anti-Ro/SSA antibodies without neonatal AVB lie within our published polynomial reference ranges. While diagnosing a 1° AVB remains controversial, more data are needed to prove that our reference ranges are helpful exclude a 1° AVB.

Cisd2 is essential to delaying cardiac aging and to maintaining heart functions.

CDGSH iron-sulfur domain-containing protein 2 (Cisd2) is pivotal to mitochondrial integrity and intracellular Ca2+ homeostasis. In the heart of Cisd2 knockout mice, Cisd2 deficiency causes intercalated disc defects and leads to degeneration of the mitochondria and sarcomeres, thereby impairing its electromechanical functioning. Furthermore, Cisd2 deficiency disrupts Ca2+ homeostasis via dysregulation of sarco/endoplasmic reticulum Ca2+-ATPase (Serca2a) activity, resulting in an increased level of basal cytosolic Ca2+ and mitochondrial Ca2+ overload in cardiomyocytes. Most strikingly, in Cisd2 transgenic mice, a persistently high level of Cisd2 is sufficient to delay cardiac aging and attenuate age-related structural defects and functional decline. In addition, it results in a younger cardiac transcriptome pattern during old age. Our findings indicate that Cisd2 plays an essential role in cardiac aging and in the heart's electromechanical functioning. They highlight Cisd2 as a novel drug target when developing therapies to delay cardiac aging and ameliorate age-related cardiac dysfunction.

Acute echocardiographic and hemodynamic response to his-bundle pacing in patients with first-degree atrioventricular block.

BACKGROUND: Atrial pacing and right ventricular (RV) pacing are both associated with adverse outcomes among patients with first-degree atrioventricular block (1°AVB). His-bundle pacing (HBP) provides physiological activation of the ventricle and may be able to improve both atrioventricular (AV) and inter-ventricular synchrony in 1°AVB patients. This study evaluates the acute echocardiographic and hemodynamic effects of atrial, atrial-His-bundle sequential (AH), and atrial-ventricular (AV) sequential pacing in 1°AVB patients. METHODS: Patients with 1°AVB undergoing atrial fibrillation ablation were included. Following left atrial (LA) catheterization, patients underwent atrial, AH- and AV-sequential pacing. LA/left ventricular (LV) pressure and echocardiographic measurements during the pacing protocols were compared. RESULTS: Thirteen patients with 1°AVB (mean PR 221 ± 26 ms) were included. The PR interval was prolonged with atrial pacing compared to baseline (275 ± 73 ms, p = .005). LV ejection fraction (LVEF) was highest during atrial pacing (62 ± 11%), intermediate with AH-sequential pacing (59 ± 7%), and lowest with AV-sequential pacing (57 ± 12%) though these differences were not statistically significant. No significant differences were found in LA or LV mean pressures or LV dP/dT. LA and LV volumes, isovolumetric times, electromechanical delays, and global longitudinal strains were similar across pacing protocols. CONCLUSION: Despite pronounced PR prolongation, the acute effects of atrial pacing were not significantly different than AH- or AV-sequential pacing. Normalizing atrioventricular and/or inter-ventricular dyssynchrony did not result in acute improvements in cardiac output or loading conditions.

Prediction of outcome in fetal autoimmune complete heart block.

Assessing cardiac function and risk stratification in a fetal anti-Sjögren syndrome type A (SSA) or anti-Sjögren syndrome type B (SSB) complete atrioventricular block (CAVB) is challenging. We aimed to evaluate the cardiovascular profile score (CVP) and its components in surveillance of fetuses with autoimmune CAVB. METHODS: Retrospective cohort review of CAVB pregnancies, excluding fetuses with significant cardiac anomalies. RESULTS: CAVBs are in 17 fetuses, diagnosed at mean gestational age of 23 ± 5 weeks. Overall mortality is 18%: 1 termination, 1 fetal demise (intrauterine fetal demise [IUFD]), and 1 postnatal death. Both mortalities had intrauterine growth restriction; IUFD had placental infarction. Presenting CVP 8.7 ± 1. No fetus had CVP <7; the score correlated with increased risk of perinatal death. The 2 mortalities had initial CVP scores of 8 and 9; both increased to 10 on subsequent exams. 30% of fetuses had low middle cerebral artery pulsatility (MCA-PI) on the last study. All had high umbilical artery pulsatility (UA-PI) throughout gestation. The 2 deaths had the lowest MCA-PI. CONCLUSION: Despite low heart rates, high CVP scores in our cohort remained high and were not predictive of mortality. Abnormalities in MCA flow reflects fetal cerebral vasodilation that may indicate altered hemodynamics and be predictive of outcomes, but data is limited. Abnormal umbilical artery (UA) flow suggests that perinatal mortality may also be related to placental disease.

Incidence of atrioventricular block with vasodilator stress SPECT: A meta-analysis.

BACKGROUND: Adenosine or regadenoson are often used with pharmacologic stress testing. Adenosine may trigger atrioventricular block (AVB). Despite its higher selectivity, regadenoson has also been associated with AVB. We studied the incidence of de novo AVB with these agents. METHODS: A comprehensive search of SCOPUS was performed from inception to March 2016. Studies of at least 10 patients, using adenosine and/or regadenoson with SPECT-MPI, reporting rates of AVB were selected for further review. RESULTS: Thirty four studies were pooled including 22,957 patients. Adenosine was used in 21 studies and regadenoson in 15. Both were administered in two studies. The estimated incidence of overall and high-grade AVB was 3.81% (95% CI 1.99%-6.19%) and 1.93% (95% CI 0.77%-3.59%), respectively. The incidence of AVB (8.58%; 95% CI 5.55%-12.21% vs 0.30%; 95% CI 0.04%-0.82%, respectively, P < .001) and high-grade AVB (5.21%; 95% CI 2.81%-8.30% vs 0.05%; 95% CI < .001%-0.19% respectively, P < .001) were higher with adenosine compared to regadenoson. CONCLUSION: AVB is seen in about 4% of patients undergoing vasodilator stress test. Both overall and high-grade AVB are more frequent with adenosine compared to regadenoson.

A novel use of cardiac resynchronization therapy-defibrillator device in hypertrophic cardiomyopathy.

Dual-chamber implantable cardioverter-defibrillator is generally used in patients with atrioventricular block and hypertrophic cardiomyopathy with preserved left ventricular ejection fraction. In the current case, a cardiac resynchronization therapy-defibrillator device was implanted in a patient with non-obstructive hypertrophic cardiomyopathy with preserved ejection fraction and atrioventricular block to achieve both more physiological pacing and life-threatening ventricular arrhythmia management.

Treating Lyme carditis high-degree AV block using a temporary-permanent pacemaker.

A 28-year-old previously healthy male presented with nonprodromal syncope and a 4-day history of chest pain, shortness of breath, and malaise. His ECG showed rapidly progressive high-degree AV block. His Suspicious Index in Lyme Carditis (SILC) score was 8, indicating high risk for Lyme carditis. Lyme serology revealed to be positive (anti-Lyme IgM). During the second day of hospitalization, the patient deteriorated his AV conduction, and a temporary-permanent pacemaker was implanted allowing ambulating in hospital the very same day. Temporary-permanent pacemakers for the management of transient high-degree heart block associated with Lyme carditis were only occasionally used in the past.

Fortuitous Identification of Fluctuating AV Block: A Case Report.

BACKGROUND: Vagally mediated atrioventricular block (AVB) may occur as a result of increased parasympathetic tone. This particular AVB is infrequently described in the literature, but its prevalence may be underestimated, as it may occur without recognition. CASE REPORT: We present a case of vagally mediated AVB that was identified by serial electrocardiography of a patient who presented to the emergency department with vomiting. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Vagally mediated AVB must be differentiated from paroxysmal, bradycardia-dependent AVB, which may progress to persistent AVB and require pacemaker placement. In an asymptomatic patient with vagally mediated AVB, pacemaker placement is contraindicated. However, if symptoms are clearly attributable to vagally mediated AVB, pacemaker placement may be reasonable.

Periventricular nodular heterotopia. / Periventrikulær nodulær heterotopi.

BACKGROUND: Periventricular nodular heterotopia (PNH) is an embryonal neuronal migration disturbance of the brain. The condition is rare and genetically heterogeneous, often caused by mutations in the FLNA gene. The most common symptoms are epileptic seizures. PNH is often associated with other conditions such as cardiovascular abnormalities. CASE PRESENTATION: A young man was admitted to hospital after a first episode of loss of consciousness. The patient was in normal general condition upon admission, and the clinical examination revealed no abnormalities. However, cerebral imaging performed upon admittance showed PNH, while an extended cardiac examination revealed atrioventricular block with the indication for a pacemaker. After pacemaker implantation and introduction of antiepileptic drug therapy, the patient has been free of symptoms. INTERPRETATION: PNH is a condition that needs multidisciplinary assessments.

Complete atrioventricular block as an initial manifestation of recurred oral cavity cancer: a case report.

BACKGROUND: Intracardiac invasion of head and neck cancer is extremely rare. Here, we report a case of recurred oral cavity cancer presenting with complete atrioventricular (AV) block caused by cardiac metastasis. CASE PRESENTATION: A 70-year-old male presented with dizziness for 2 days. He had a history of oral cavity cancer a year ago, and the tumor was treated by surgical excision after induction chemotherapy and concurrent chemoradiation therapy. Electrocardiography showed complete AV block with ventricular escape rate of 43 beats per minute. Cardiac imaging revealed about 4.0 × 2.0 cm-sized mass invading interventricular septum and AV nodes and protruding into the right ventricle. Magenetic resonance imaging of head and neck demonstrated recurred mass in oral cavity and maxillary sinus. Fluorodeoxyglucose-positron emission tomography showed hypermetabolic lesion in both oral cavity and the heart around interventricular septum and atrioventricular node indicating recurred oral cavity cancer with cardiac metastasis. Permament pacemaker of DDD type was implanted for the symptomatic complete AV block, and palliative chemotherapy was initiated. CONCLUSION: The present case demonstrated that oral cavity cancer can metastasize to the heart, and complete AV block may be an initial manifestation of the recurrence of extracardiac cancer with intracardiac invasion.

Maternal steroid therapy for fetuses with second-degree immune-mediated congenital atrioventricular block: a systematic review and meta-analysis.

INTRODUCTION: The aim of this study was to explore the effect of maternal fluorinated steroid therapy on fetuses affected by second-degree immune-mediated congenital atrioventricular block. MATERIAL AND METHODS: Studies reporting the outcome of fetuses with second-degree immune-mediated congenital atrioventricular block diagnosed on prenatal ultrasound and treated with fluorinated steroids compared with those not treated were included. The primary outcome was the overall progression of congenital atrioventricular block to either continuous or intermittent third-degree congenital atrioventricular block at birth. Meta-analyses of proportions using random effect model and meta-analyses using individual data random-effect logistic regression were used. RESULTS: Five studies (71 fetuses) were included. The progression rate to congenital atrioventricular block at birth in fetuses treated with steroids was 52% (95% confidence interval 23-79) and in fetuses not receiving steroid therapy 73% (95% confidence interval 39-94). The overall rate of regression to either first-degree, intermittent first-/second-degree or sinus rhythm in fetuses treated with steroids was 25% (95% confidence interval 12-41) compared with 23% (95% confidence interval 8-44) in those not treated. Stable (constant) second-degree congenital atrioventricular block at birth was present in 11% (95% confidence interval 2-27) of cases in the treated group and in none of the newborns in the untreated group, whereas complete regression to sinus rhythm occurred in 21% (95% confidence interval 6-42) of fetuses receiving steroids vs. 9% (95% confidence interval 0-41) of those untreated. CONCLUSIONS: There is still limited evidence as to the benefit of administered fluorinated steroids in terms of affecting outcome of fetuses with second-degree immune-mediated congenital atrioventricular block.

Resolution of fetal second-degree atrioventricular block.

Fetal atrioventricular (AV) block is a rare and potentially devastating condition. Most commonly fetal AV block is mediated by maternal lupus antibodies which cause irreversible damage to the AV node. For many fetuses, the only potential intervention is premature delivery and highly invasive pacemaker implantation. However, there exists a small subset of fetuses with non-immune mediated AV block who appear to have far better outcomes, with potential for spontaneous resolution and a return to sinus rhythm. Despite this, it is not clear that prenatal counseling takes this fact into account. We describe a series of three patients with non-immune fetal second-degree AV block with spontaneous resolution prior to delivery, underscoring the need for appropriate prenatal counseling in this scenario.

A premature low-birth-weight infant with congenital complete atrioventricular block and myocarditis successfully treated by staged pacemaker implantation.

Congenital complete atrioventricular block is a known lethal condition. Although antenatal diagnosis and the technical advances of pacemaker treatment have reduced its mortality, treatment of premature babies with significant myocardial damage remains a challenge. In this paper, we report the case of a premature low-birth-weight infant with congenital complete atrioventricular block and extremely low ventricular rate, fetal hydrops, and myocarditis who was successfully treated with staged permanent pacemaker implantation.

Prevalence of Left Ventricular Dyssynchrony in Patients with Congenital Atrioventricular Block and Long-Term Pacing: A Three-Dimensional Echocardiographic Study.

BACKGROUND: Left ventricular (LV) dysfunction is the major reason for poor outcomes in patients with congenital complete atrioventricular block (CCAVB) and pacemaker. Long-term pacing has been associated with LV mechanical dyssynchrony. However, the relationship of dyssynchrony and LV dysfunction is not clear. OBJECTIVE: We sought to evaluate the prevalence of LV dyssynchrony by real time three-dimensional echocardiography (RT3DE) in patients with CCAVB and its association with LV dysfunction. In addition, we evaluated the agreement between RT3DE and tissue Doppler imaging (TDI) for detecting LV dyssynchrony. METHOD: We studied 50 patients [median age 20 years old (5 months to 62 years), 68% women] with CCAVB and pacemaker who underwent complete two-dimensional echocardiography and RT3DE. LV dyssynchrony was considered if the systolic dyssynchrony index (SDI) was ≥ 5%. Intraventricular mechanical delay was defined by TDI when differences in electromechanical activation between LV walls were > 65 msec. RESULTS: LV systolic dysfunction was present in 16 patients (32%) by two-dimensional and in 20 patients (40%) by RT3DE. There was a good correlation between LV ejection fraction by two-dimensional and RT3DE (r = 0.75; P < 0.001). Fourteen (28%) patients had intraventricular dyssynchrony by TDI, while 12 (24%) had intraventricular dyssynchrony by RT3DE. There was a good agreement between LV dyssynchrony by TDI and RT3DE (Kappa = 0.735; P < 0.001). There was a negative correlation between LV ejection fraction and SDI obtained by RT3DE (r = -0.58; P < 0.001) CONCLUSIONS: In patients with CCAVB and long-term pacing, LV dyssynchrony occurred in one-third of patients and was related to LV dysfunction. There was a good correlation between dyssynchrony obtained by RT3DE and TDI.

Clinical settings leading to presystolic tricuspid regurgitation.

PURPOSE: Few studies describe diastolic (presystolic) tricuspid regurgitation (DTR) mainly in the context of atrioventricular conduction abnormalities. Little is known about its occurrence in the other clinical settings. METHODS: We identified patients with DTR recorded during routine echocardiographic examinations. DTR was defined as low velocity backward flow through the tricuspid valve orifice during end-diastole recorded with a continuous and/or pulsed-wave Doppler and/or color-coded M-mode Doppler echocardiography. RESULTS: Diastolic tricuspid regurgitation was present in a wide variety of clinical entities. Of the 23 patients with DTR 6 patients had ischemic and 10 dilated cardiomyopathy. Others had clinical conditions including: inappropriate pacemaker settings, decompensated hypertrophic cardiomyopathy, biventricular dysfunction following orthotropic heart transplantation, torrential aortic regurgitation, low ejection fraction aortic stenosis, advanced endocardial fibroelastosis, and complex congenital heart disease. Twenty of 23 patients had significantly impaired right ventricle (RV) systolic function. Systolic tricuspid regurgitation was estimated as moderate or severe in 13 cases and mild in the remaining 10 cases. RV systolic pressure was significantly elevated in all but 2 cases. In all but 4 cases DTR was transient. The persistence of DTR was associated with severe pulmonary hypertension, severe biventricular failure, and persistent severe pulmonary regurgitation. CONCLUSIONS: Diastolic tricuspid regurgitation may be encountered in a variety of clinical settings and should be sought for especially in patients with advanced RV systolic dysfunction, pulmonary hypertension, pulmonary regurgitation, or conduction abnormalities. Significant systolic regurgitation is not prerequisite for the development of DTR.

Lethal arrhythmias in Tbx3-deficient mice reveal extreme dosage sensitivity of cardiac conduction system function and homeostasis.

TBX3 is critical for human development: mutations in TBX3 cause congenital anomalies in patients with ulnar-mammary syndrome. Data from mice and humans suggest multiple roles for Tbx3 in development and function of the cardiac conduction system. The mechanisms underlying the functional development, maturation, and maintenance of the conduction system are not well understood. We tested the requirements for Tbx3 in these processes. We generated a unique series of Tbx3 hypomorphic and conditional mouse mutants with varying levels and locations of Tbx3 activity within the heart, and developed techniques for evaluating in vivo embryonic conduction system function. Disruption of Tbx3 function in different regions of the developing heart causes discrete phenotypes and lethal arrhythmias: sinus pauses and bradycardia indicate sinoatrial node dysfunction, whereas preexcitation and atrioventricular block reveal abnormalities in the atrioventricular junction. Surviving Tbx3 mutants are at increased risk for sudden death. Arrhythmias induced by knockdown of Tbx3 in adults reveal its requirement for conduction system homeostasis. Arrhythmias in Tbx3-deficient embryos are accompanied by disrupted expression of multiple ion channels despite preserved expression of previously described conduction system markers. These findings indicate that Tbx3 is required for the conduction system to establish and maintain its correct molecular identity and functional properties. In conclusion, Tbx3 is required for the functional development, maturation, and homeostasis of the conduction system in a highly dosage-sensitive manner. TBX3 and its regulatory targets merit investigation as candidates for human arrhythmias.