Frequent cyclic variation of heart rate is associated with left ventricular diastolic dysfunction in patients without ischemia.

BACKGROUND: Cyclic variation of heart rate (CVHR) associated with sleep-disordered breathing reflects cardiac autonomic responses to apneic/hypoxic stress. However, the association of CVHR with cardiac function is unclear. METHODS: We investigated a total of 181 patients who underwent both 24-hour Holter electrocardiography (ECG) and quantitative gated single-photon emission computed tomography (SPECT) myocardial functional imaging, excluding patients with atrial fibrillation, myocardial infarction, structural heart disease, and implantable devices, from January 2017 to July 2018. The number of CVHR per hour (CVHR index) in sleeping-time Holter ECG was compared with the parameters of left ventricular (LV) systolic and diastolic functions assessed by cardiac SPECT functional imaging, peak filling rate (PFR), first-third mean filling rate (1/3 MFR), and time to peak filling rate (TTPF). RESULTS: In all patients, the CVHR index was not associated with any parameters of cardiac functions. However, in a propensity score-matched subgroup of patients without ischemia (N = 39), the CVHR index was negatively correlated with PFR (r = -0.35, P < .05) and 1/3 MFR (r = -0.37, P < .05) but positively correlated with TTPF (r = 0.43, P < .01) and was not correlated with LV ejection fraction. Multivariate linear regression analysis revealed that high CVHR index was independently associated with LV diastolic dysfunction, even after adjusting for the relative wall thickness and LV mass index assessed by echocardiography. CONCLUSION: These results indicate that the high frequency of CVHR in sleeping time is associated with LV diastolic dysfunction in nonischemic patients, irrespective of LV geometry.

Impact of left atrial size on isolation area in the acute phase of pulmonary vein isolation using 28 mm cryoballoon.

BACKGROUND: The impact of left atrial (LA) size on isolation area (ISA) using a 28-mm second-generation cryoballoon (CB) in the acute phase after pulmonary vein isolation (PVI) and the differences of CB from contact force-guided radiofrequency (RF) ablation have not been fully investigated. METHODS: We examined 85 consecutive patients (CB group, 35; RF group, 50) with drug-refractory paroxysmal atrial fibrillation who underwent their first PVI procedure at two institutions. We evaluated ISA after PVI using 3D-Merge computed tomography images (GE Healthcare, Little Chalfont, UK) and high-resolution electroanatomical mapping. RESULTS: Total ISA was significantly smaller in the CB group (20.6 ± 6.0 cm2 ) than in the RF group (29.0 ± 7.1 cm2 ; P < 0.0001). In the CB group, ISA of the left pulmonary vein (LPV), right pulmonary vein (RPV), and total ISA were not correlated with the left atrial surface area (LASA). The ratios of ISA to LASA (%ISA) of LPV and total ISA negatively correlated with LASA in the CB group (LPV: r = -0.4001, P = 0.0173; total ISA: r = -0.4733, P = 0.0041). In contrast, in the RF group, ISA of LPV, RPV, and total ISA positively correlated with LASA; (LPV: r = 0.5155, P = 0.001; RPV: r = 0.6398, P < 0.0001; total ISA: r = 0.7299, P < 0.0001). CONCLUSION: ISA created using CB was significantly smaller than that using RF and did not change regardless of LASA increment. Differences in ISA between the two groups became more prominent in the large atrium.

General anesthesia improves contact force and reduces gap formation in pulmonary vein isolation: a comparison with conscious sedation.

Compared to conscious sedation (CS), the use of general anesthesia (GA) in pulmonary vein isolation (PVI) is associated with a lower recurrence rate of atrial fibrillation (AF). GA may improve catheter stability and mapping system accuracy compared to CS, but its influence on contact force (CF) parameters during ipsilateral PVI has not previously been investigated. The study population comprised 176 consecutive patients (107 in GA group and 69 in CS group) with AF who underwent their first PVI procedure. We retrospectively assessed CF parameters, force-time integral (FTI), FTI/wall thickness during anatomical ipsilateral PVI and long-term outcome after ablation. Complete PVI with single continuous circular lesions around the ipsilateral PVs was achieved in 54 patients (50.5%) in the GA group but only 24 patients (34.8%) in the CS group (P = 0.04). The distribution of gaps did not differ between the groups. All CF parameters were significantly higher in the GA group than in the CS group (average CF: 19.4 ± 8.7 vs. 16.7 ± 7.7 g, P < 0.0001; FTI: 399.0 ± 262.5 vs. 293.9 ± 193.4 gs, P < 0.0001; FTI/wall thickness: 155.5 ± 106.1 vs. 115.7 ± 85.5 gs, P < 0.0001). GA was associated with lower AF recurrence rate in patients with paroxysmal AF but not with persistent AF. Compared with CS, GA improves CF parameters, FTI and FTI/wall thickness, and reduced gap formation after ipsilateral PVI.

Short-term rapid atrial pacing alters the gene expression profile of rat liver: Cardiohepatic interaction in atrial fibrillation.

BACKGROUND: Atrial fibrillation (AF) activates the coagulation system, leading to hypercoagulation of the blood. The liver is a major source of prothrombotic molecules. OBJECTIVE: This study aimed to clarify whether cardiohepatic interactions are involved in AF-related hypercoagulation. METHODS: We compared gene expression profiles of human liver tissue between patients with AF and sinus rhythm. An AF model was created by rapid atrial pacing (RAP) at a frequency of 1200 beats/min in anesthetized 10-week-old Sprague-Dawley rats. Livers, atria, and peripheral blood cells were collected and analyzed after 12 hours of RAP. RESULTS: DNA microarray analysis revealed marked changes in the gene expression profile of human liver of patients with AF. The extrinsic prothrombin activation pathway showed the most prominent change in 354 BioCarta pathways. Twelve hours of RAP also markedly altered the gene expression profile of rat liver. RAP markedly augmented the hepatic messenger RNA expression of fibrinogen chains, prothrombin, coagulation factor X, and antithrombin III. The augmented fibrinogen production by RAP was accompanied by increased of interleukin 6 (IL-6) messenger RNA expression in peripheral blood cells, enhanced monocyte chemoattractant protein-1 expression in the liver, infiltrated cluster of differentiation 11b-positive mononuclear cells in the liver, and enhanced signal transducer and activator of transcription 3 (STAT3) phosphorylation in the nuclei of hepatocytes. STAT3 phosphorylation and increased fibrinogen and coagulation factor X production by RAP were suppressed by pretreatment with IL-6 neutralizing antibody. CONCLUSION: Rapid atrial excitation mimicking paroxysmal AF remotely altered the hepatic gene expression of prothrombotic molecules. Increased fibrinogen expression in the liver by RAP was mediated by activation of the IL-6/STAT3 signaling pathway in the peripheral blood and liver.

Separated right and left ventricular excitation during right ventricular septal pacing in a patient with narrow QRS wave: a case report.

INTRODUCTION: Right ventricular septal pacing is thought to be better than right ventricular apical pacing for shortening the QRS duration and for preserving left ventricular function. However, right ventricular septal pacing may not be effective in all cases. In this case report, we present a rare case in which right ventricular septal pacing induced thoroughly separated right and left ventricular excitation despite the presence of a relatively narrow QRS wave during atrium-only pacing. CASE PRESENTATION: We report a case of 63-year-old Japanese man with cardiomyopathy with an implantable cardioverter defibrillator placement for ventricular tachycardia. Three years after implantation, he developed second-degree atrio-ventricular block. Therefore, atrio-ventricular sequential pacing was started; then his heart failure was much worsened. His electrocardiogram showed a dissociated biphasic QRS wave during right ventricular high-septal pacing, despite the presence of a non-fragmented QRS morphology during atrium-only pacing. An activation map during right ventricular high-septal pacing showed that right ventricular conduction started at the pacing site and ended at the right ventricular basal inferior site. Subsequently after a 10 ms interval, left ventricular conduction started at the left ventricular posteroseptum and ended at the left ventricular lateral wall. These data indicate that during right ventricular high-septal pacing, the first component of the QRS wave supposedly reflects only right ventricular excitation and the second component only left ventricular excitation. Also due to the intracardiac electrograms, it was assumed that this phenomenon was caused by transversely limited severe transseptal conduction disturbance. CONCLUSION: It should be noted that even ventricular septal pacing could evoke harmful interventricular dyssynchrony due to transversely limited severe septal conduction disturbance, despite the presence of a relatively narrow QRS wave.

Acute myocardial infarction following food-dependent exercise-induced anaphylaxis.

A 70-year-old man with a history of food-dependent exercise-induced anaphylaxis (FDEIA) since age 50 was admitted to the emergency department with chest pain and urticaria caused by FDEIA. Coronary angiography revealed total occlusion of the proximal left anterior descending coronary artery. After thrombus aspiration, a bare metal stent was placed into the culprit lesion, resulting in no residual stenosis. Urticaria disappeared on the second hospital day. This is the first reported case, to our knowledge, in which acute myocardial infarction followed FDEIA. Physicians should be aware of acute myocardial infarction as a rare but potential complication of FDEIA.

Swallow syncope, a case report and review of the literature.

Swallow syncope is a relatively rare syndrome that is treatable when diagnosed. A 66-year-old woman was referred to the department of cardiology because she had been suffering from recurrent syncopal attacks associated with swallowing. An ambulatory electrocardiogram revealed atrial and ventricular asystoles immediately after swallowing soup or tea that were reproducible (max. RR 3.5 s). An electrophysiological study did not detect sinus nodal or atrioventricular nodal dysfunction. The patient had no underlying esophageal disease or cardiac disorder. The patient's symptoms resolved after permanent pacemaker implantation. This report reviews the diagnosis, mechanism and management of swallow syncope.