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.
Background:
The unfolded protein response (UPR) plays a pivotal role in ischemia–reperfusion (I/R) injury in various organs such as heart, brain, and liver. Sodium 4-phenylbutyrate (PBA) reportedly ...acts as a chemical chaperone that reduces UPR. In the present study, we evaluated the effect of PBA on reducing the UPR and protecting against myocardial I/R injury in mice.
Methods:
Male C57BL/6 mice were subjected to 30-minute myocardial I/R, and were treated with phosphate-buffered saline (as a vehicle) or PBA.
Results:
At 4 hours after reperfusion, mice treated with PBA had reduced serum cardiac troponin I levels and numbers of apoptotic cells in left ventricles (LVs) in myocardial I/R. Infarct size had also reduced in mice treated with PBA at 48 hours after reperfusion. At 2 hours after reperfusion, UPR markers, including eukaryotic initiation of the factor 2α-subunit, activating transcription factor-6, inositol-requiring enzyme-1, glucose-regulated protein 78, CCAAT/enhancer-binding protein (C/EBP) homologous protein, and caspase-12, were significantly increased in mice treated with vehicle compared to sham-operated mice. Administration of PBA significantly reduced the I/R-induced increases of these markers. Cardiac function and dimensions were assessed at 21 days after I/R. Sodium 4-phenylbutyrate dedicated to the improvement of cardiac parameters deterioration including LV end-diastolic diameter and LV fractional shortening. Consistently, PBA reduced messenger RNA expression levels of cardiac remodeling markers such as collagen type 1α1, brain natriuretic peptide, and α skeletal muscle actin in LV at 21 days after I/R.
Conclusion:
Unfolded protein response mediates myocardial I/R injury. Administration of PBA reduces the UPR, apoptosis, infarct size, and preserved cardiac function. Hence, PBA may be a therapeutic option to attenuate myocardial I/R injury in clinical practice.
It is vital to identify cardiac involvement (CI) in patients with sarcoidosis as the condition could initially lead to sudden cardiac death. Although the T wave amplitude in lead aVR (TWAaVR) is ...reportedly associated with adverse cardiac events in various cardiovascular diseases, only scarce data are available concerning the utility of lead aVR in identifying CI in patients with sarcoidosis. We retrospectively investigated the diagnostic values of TWAaVR in patients with sarcoidosis in comparison with conventional electrocardiography parameters such as bundle branch block (BBB). From January 2006 to December 2014, 93 consecutive patients with sarcoidosis were enrolled (mean age, 55.7 ± 15.7 years; male, 31 %; cardiac involvement,
n
= 26). TWAaVR showed the greatest sensitivity (39 %) and specificity (92 %) in distinguishing between sarcoidosis patients with and without CI, at a cutoff value of −0.08 mV. The diagnostic value of BBB for cardiac involvement was significantly improved when combined with TWAaVR (sensitivity: 61–94 %, specificity: 97–89 %, area under the curve: 0.79–0.92,
p
= 0.018). Multivariate logistic regression analysis indicated that TWAaVR and BBB were independent electrocardiography parameters associated with CI. In summary, we observed that sarcoidosis patients exhibiting a high TWAaVR were likely to have CI. Thus, the application of a combination of BBB with TWAaVR may be useful when screening for CI in sarcoidosis patients.
Obstructive sleep apnea syndrome (OSAS) is associated with augmented sympathetic nerve activity, as assessed by multi-unit muscle sympathetic nerve activity (MSNA). However, it is still unclear ...whether single-unit MSNA is a better reflection of sleep apnea severity according to the apnea-hypopnea index (AHI). One hundred and two OSAS patients underwent full polysomnography and single- and multi-unit MSNA measurements. Univariate and multivariate regression analysis were performed to determine which parameters correlated with OSAS severity, which was defined by the AHI. Single- and multi-unit MSNA were significantly and positively correlated with AHI severity. The AHI was also significantly correlated with multi-unit MSNA burst frequency (r = 0.437, p < 0.0001) and single-unit MSNA spike frequency (r = 0.632, p < 0.0001). Multivariable analysis revealed that SF was correlated most significantly with AHI (T = 7.27, p < 0.0001). The distributions of multiple single-unit spikes per one cardiac interval did not differ between patients with an AHI of <30 and those with and AHI of 30-55 events/h; however, the pattern of each multiple spike firing were significantly higher in patients with an AHI of >55. These results suggest that sympathetic nerve activity is associated with sleep apnea severity. In addition, single-unit MSNA is a more accurate reflection of sleep apnea severity with alternation of the firing pattern, especially in patients with very severe OSAS.
Sympathetic activation in chronic heart failure (CHF) is greatly augmented at rest but the response to exercise remains controversial.
We previously demonstrated that single-unit muscle sympathetic ...nerve activity (MSNA) provides a more detailed description
of the sympathetic response to physiological stress than multi-unit nerve recordings. The purpose of this study was to determine
whether the reflex response and discharge properties of single-unit MSNA are altered during handgrip exercise (HG, 30% of
maximum voluntary contraction for 3 min) in CHF patients (New York Heart Association functional class II or III, n = 16) compared with age-matched healthy control subjects ( n = 13). At rest, both single-unit and multi-unit indices of sympathetic outflow were augmented in CHF compared with controls
( P < 0.05). However, the percentage of cardiac intervals that contained one, two, three or four single-unit spikes were not
different between the groups. Compared to the control group, HG elicited a larger increase in multi-unit total MSNA (Î1002
± 50 compared with Î636 ± 76 units min â1 , P < 0.05) and single-unit MSNA spike incidence (Î27 ± 5 compared with Î8 ± 2 spikes (100 heart beats) â1 ), P < 0.01) in the CHF patients. More importantly, the percentage of cardiac intervals that contained two or three single-unit
spikes was increased ( P < 0.05) during exercise in the CHF group only (Î8 ± 2% and Î5 ± 1% for two and three spikes, respectively). These results
suggest that the larger multi-unit total MSNA response observed during HG in CHF is brought about in part by an increase in
the probability of multiple firing of single-unit sympathetic neurones.
The main etiology of constrictive pericarditis (CP) has changed from tuberculosis to therapeutic mediastinal radiation and cardiac surgery. Occult constrictive pericardial disease (OCPD) is a covert ...disease in which CP is manifested in a condition of volume overload.
A 60-year-old patient with a history of thoracic radiation therapy for non-Hodgkin's lymphoma (40 years earlier) was transferred to our hospital for treatment of repeated congestive heart failure. For a preoperative hemodynamic study, pre-hydration with intravenous normal saline (50 mL/hour) was used to manifest the pericardial disease and prevent contrast-induced nephropathy. The hemodynamic study showed a right ventricular dip-plateau pattern and discordance of right and left ventricular systolic pressures during inspiration, which was not seen in the volume-controlled state. These responses were concordant with OCPD. A pericardiectomy, aortic valve replacement, and mitral and tricuspid valve repair were performed. Postoperatively, the heart failure was controlled with standard medication.
This case revealed a volume-induced change in hemodynamics in OCPD with severe combined valvular heart disease, which suggests the importance of considering OCPD in patients who had undergone radiation therapy 40 years before.
Most cases of swallowing‐induced atrial tachycardia require radiofrequency catheter ablation for a permanent cure; however, the arrhythmia subsided after temporary prescription of verapamil in a ...patient with genotyped hypertrophic cardiomyopathy.
Most cases of swallowing‐induced atrial tachycardia require radiofrequency catheter ablation for a permanent cure; however, the arrhythmia subsided after temporary prescription of verapamil in a patient with genotyped hypertrophic cardiomyopathy.
The prognosis of pulmonary arterial hypertension (PAH) has significantly improved over the past two decades due to advances in medications, including pulmonary vasodilators. However, the side effects ...of these drugs remain problematic in some patients. A 51-year-old woman with chronic hepatitis C was diagnosed with PAH 7 years before presenting to our hospital. She was unable to continue her treatment with pulmonary vasodilators due to various side effects. She had a World Health Organization functional class of IV and was started on continuous infusion of prostaglandin I2 (PGI2). This therapy improved her symptoms, including dyspnea and fatigue. However, she began to complain of abdominal distension after 4 months of PGI2 therapy. Computed tomography showed significant hepatosplenomegaly. Her abdominal distension improved slightly after decreasing PGI2 treatment, but her dyspnea on exertion was exacerbated. She died 12 years after diagnosis of PAH due to uncontrollable heart failure. Here, we describe a rare case of PAH with hepatosplenomegaly after administration of PGI2.
<Learning objective: Intravenous continuous prostaglandin (PG) I2 therapy is useful for the treatment of severe pulmonary arterial hypertension (PAH). However, it has numerous side effects that are difficult to control. We report a rare case of PAH with chronic hepatitis C that resulted in hepatosplenomegaly after PGI2 administration. In cases of chronic liver disease, it is important to keep in mind that administration of PGI2 may result in hepatosplenomegaly.>
This study sought to investigate whether the presence of J waves was associated with cardiac events in patients with hypertrophic cardiomyopathy (HCM).
It has been uncertain whether the presence of J ...waves predicts life-threatening cardiac events in patients with HCM.
This study evaluated consecutive 338 patients with HCM (207 men; age 61 ± 17 years of age). A J-wave was defined as J-point elevation >0.1 mV in at least 2 contiguous inferior and/or lateral leads. Cardiac events were defined as sudden cardiac death, ventricular fibrillation or sustained ventricular tachycardia, or appropriate implantable cardiac defibrillator therapy. The study also investigated whether adding the J-wave in a conventional risk model improved a prediction of cardiac events.
J waves were seen in 46 (13.6%) patients at registration. Cardiac events occurred in 31 patients (9.2%) during median follow-up of 4.9 years (interquartile range: 2.6 to 7.1 years). In a Cox proportional hazards model, the presence of J waves was significantly associated with cardiac events (adjusted hazard ratio: 4.01; 95% confidence interval CI: 1.78 to 9.05; p = 0.001). Compared with the conventional risk model, the model using J waves in addition to conventional risks better predicted cardiac events (net reclassification improvement, 0.55; 95% CI: 0.20 to 0.90; p = 0.002).
The presence of J waves was significantly associated with cardiac events in HCM. Adding J waves to conventional cardiac risk factors improved prediction of cardiac events. Further confirmatory studies are needed before considering J-point elevation as a marker of risk for use in making management decisions regarding risk in patients with HCM.
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