Background: Right ventricular (RV) pacing alters left ventricular (LV) mechanical activation, resulting in adverse impacts on LV function. This study was aimed to investigate the acute effect of RV ...apical (RVA) and septal pacing (RVS) on LV dyssynchrony and function using speckle tracking echocardiography. Methods and Results: The 103 patients (749 years) with symptomatic bradyarrhythmia and preserved LV ejection fraction, and 50 age-matched control subjects were studied. All patients received a permanent pacemaker and were randomly assigned into 2 groups (RVA: n=51, RVS: n=52). After insertion, patients underwent an echocardiographic study during RV pacing. LV dyssynchrony and global strain parameters were analyzed using speckle tracking echocardiography. The QRS width and dyssynchrony indices by longitudinal and radial strain were significantly greater in RVA than in both the control and RVS. The LV longitudinal dyssynchrony index was significantly related to global longitudinal strain (GLS) among 103 patients receiving RV pacing (R2=0.25, P<0.0001). The GLS in RVA were the lowest among the 3 groups (GLS: Control: -18.22.4%, RVA: -14.33.1%, P<0.001 vs. control, RVS: -16.82.7%, P<0.01 vs. RVA). Conclusions: RVA created heterogeneous LV contraction, which resulted in deteriorated LV longitudinal contraction. RVS could be a better pacing alternative in terms of less LV dyssynchrony and better longitudinal function compared to RVA. (Circ J 2011; 75: 1609-1615)
Adaptive servo-ventilation (ASV) therapy is a novel modality of noninvasive positive pressure ventilation and is now widely utilized to treat patients with chronic heart failure (CHF). However, there ...has been no clinical study of the effect of ASV therapy on readmission and cost-effectiveness for the treatment of CHF. The present study was conducted to evaluate the clinical efficacy and cost-effectiveness of home ASV therapy in 45 patients with a history of two or more admissions a year for worsening CHF. Seven patients refused to undergo chronic ASV therapy and three died. Thus, 35 patients were eventually enrolled in the present study. New York Heart Association class (2.8 ± 0.4 versus 2.3 ± 0.5,
p
< 0.001), log plasma B-type natriuretic peptide level (2.53 ± 0.44 versus 2.29 ± 0.40 pg/mL,
p
< 0.0001), left atrial dimension (47.5 ± 7.0 versus 44.9 ± 7.6 mm,
p
= 0.014), and mitral regurgitation area ratio (20.3 ± 12.1 versus 16.9 ± 8.9%,
p
= 0.007) decreased significantly after 12 months of ASV therapy. The frequency of hospitalization after ASV was significantly lower than before ASV (1.0 ± 1.0 versus 2.3 ± 0.5 times/year/patient,
p
< 0.0001). ASV also decreased the duration of hospitalization from 64.4 ± 46.5 to 22.8 ± 27.5 days/year/patient (
p
< 0.0001). Consequently, the total medical costs were reduced by 37% after ASV (1.95 ± 1.37 versus 3.11 ± 1.75 million yen/patient,
p
= 0.003). ASV therapy reduced readmissions and medical costs in patients with CHF.
Arrhythmias are associated with reduced quality of life and poor prognosis in patients with hypertrophic cardiomyopathy (HCM). Recent genome-wide association studies revealed that a nonsynonymous ...single nucleotide polymorphism, rs6795970, in the SCN10A gene was associated with the PR interval. We examined whether the PR prolonging allele (A allele) in the SCN10A gene may be associated with cardiac conduction abnormalities in HCM patients. We genotyped the polymorphism in 149 HCM patients. Conduction abnormalities were defined as first-degree heart block, bundle-branch block, and bifascicular heart block. Patients were divided into two groups: group A consisted of 122 patients (82%) without a conduction abnormality; and group B consisted of 27 patients (18%) with one or more cardiac conduction abnormalities. The frequency distribution of the SCN10A genotypes (G/G, G/A, and A/A) among the patients with HCM was 71%, 26%, and 3%, respectively. A cardiac conduction abnormality was documented in 9% with G/G and 40% with G/A or A/A. There was a significant difference in the genotype distribution between the two groups (P = 0.0002). In the dominant A allele model, there was a significant difference in genotypes between the two groups (P < 0.0001). In addition, the A allele remained significant after adjusting for other covariates in a multivariate model (odds ratio = 6.30 95% confidence interval: 2.24 to 19.09, P = 0.0005). The rs6795970 in the SCN10A gene, which is reported to carry a high risk of heart block, might be associated with cardiac conduction abnormalities in HCM patients.
Imaging with fluorodeoxyglucose (FDG) PET/CT is used to diagnose patients with cardiac sarcoidosis (CS). However, its specificity is relatively low. We aimed to demonstrate that higher diagnostic ...specificity for CS can be obtained using quantitative methodology to analyze PET/CT.
A total of 125 consecutive patients with suspected CS were enrolled in the study. After clinical assessment and cardiac imaging studies, the patients underwent FDG PET/CT imaging after eating a low-carbohydrate diet followed by an overnight fast lasting ≥18h. For visual analysis, fusion and maximum intensity projection images were reviewed. For quantitative analysis, the maximum standardized uptake value (SUVmax) within the myocardium was obtained.
Of the 92 patients who met study inclusion criteria, 37 were diagnosed with CS. Myocardial SUVmax was significantly higher in patients with CS compared with non-CS patients (9.5±4.8 vs. 3.0±1.7, p<0.0001). The area under the curve by receiver operating characteristic analysis was 0.960 for SUVmax. Using a cut-off value of 4.0, the sensitivity was 97.3% and specificity was 83.6% for diagnosing CS, which is more accurate than visual analysis. Moreover, SUVmax was the only significant predictor of CS among 10 clinical and imaging variables. In 18 patients who received steroid therapy with a mean follow-up duration of 6.4±5.2months, SUVmax significantly decreased from 9.8±4.2 to 5.5±3.5 (p=0.003).
When evaluated by quantification of myocardial SUVmax, FDG PET/CT imaging provides high sensitivity and specificity for diagnosing CS.
Summary Background Two-dimensional speckle tracking echocardiography (2D-STE) is a novel technology that directly measures regional left ventricular (LV) wall contraction. This study aimed to ...directly measure inner-layer thickening (radial strain) of the LV using 2D-STE, and to examine the relationship between radial strain and the degree of hypertrophy. Methods The study enrolled 63 untreated hypertensive patients with normal geometry ( N group, n = 32) or concentric hypertrophy (CH group, n = 31), classified according to LV mass index (LVMI) and relative wall thickness (RWT). Thirty normotensive subjects ( C group, n = 30) served as controls. Radial strain ( ε ) in the inner half ( εi ) and all layers of the LV wall ( εa ) were calculated from the LV short-axis view by 2D-STE. Results LV ejection fraction did not differ significantly among the groups. However, εi and εa were significantly lower in the CH group compared with the C and N groups ( p < 0.01). A ratio of εi to εa was significantly lower in the CH group compared with the C and N groups ( p < 0.01). A multivariate regression model that included midwall fractional shortening, E / e ′, LVMI, RWT, and LV ejection fraction showed that LVMI ( p = 0.002) and RWT ( p = 0.014) were independent predictors ( R2 = 0.59) of εi. Conclusion Radial strain in the inner half layer of the LV wall decreases in parallel with the degrees of LV concentricity and hypertrophy in hypertensive patients. Radial strain in the inner half layer may identify subtle systolic dysfunction even in hypertensive patients with preserved LV chamber function.
Background The feasibility of using cardiac multidetector-row computed tomography (MDCT) technology in the quantitative assessment of myocardial blood flow (MBF) using the adenosine triphosphate ...(ATP) load technique was investigated in the present study. Methods and Results The study group comprised 14 patients (11 men, 3 women, age range 52-79 years, mean age 69.2 years) who underwent cardiac cine MDCT using the ATP-load technique. MBF was estimated from the slope of the linear regression equation with Patlak plots analysis. The overall average MBF was 1.83±0.62 ml · g-1 · min-1. Mean MBF in territories with stenosis on coronary angiography was 1.19±0.36 ml · g-1 · min-1 and 2.06±0.54 ml · g-1 · min-1 (p<0.01) in territories without stenosis. The average MBF in territories with moderate to severe ischemia on myocardial perfusion scintigraphy was 1.32±0.14 ml ·g-1 · min-1 and 1.95±0.64 ml · g-1 · min-1 (p<0.01) in territories without ischemia. Conclusion MDCT can be used to quantify MBF using first-pass dynamic data. (Circ J 2008; 72: 1086 - 1091)
Left atrial (LA) enlargement is an early sign of hypertensive heart disease. Insulin resistance and obesity, integral components of metabolic syndrome, are closely associated with the development of ...hypertension. However, few echocardiographic studies have assessed the relations of insulin resistance and obesity to LA size in hypertensive patients. We enrolled 106 never-treated hypertensive patients (57 men and 49 women) to assess the possible relations of insulin resistance and obesity to LA size. Insulin resistance was estimated using the homeostasis model assessment (HOMA) formula. Echocardiographically determined LA dimension, left ventricular (LV) mass and relative wall thickness (RWT) were measured as markers of LA size, LV hypertrophy and LV geometry. The E/A ratio estimated by transmitral flow velocity was measured as a marker of LV diastolic function. In addition, body mass index (BMI) was calculated as weight (kg) divided by height (m)(2) as a marker of obesity. Multivariable regression analyses showed that BMI was the strongest independent predictor of LA size (P<0.0001), followed by the HOMA value (P=0.0003). However, LV mass, RWT and the E/A ratio did not bear significant relations to LA size. There were no sex-specific differences in the relations of HOMA value or BMI to LA size. In conclusion, LA size is influenced by insulin resistance and obesity, integral components of the metabolic syndrome, independently of LV hypertrophy, LV geometry or LV diastolic function in nondiabetic Japanese hypertensive patients.
Background: Sustained cardiac adrenergic stimulation has been implicated in the progression of cardiovascular events in patients with dilated cardiomyopathy (DCM). Our group hypothesized that a ...combination of polymorphisms that result in increased synaptic norepinephrine release and enhanced receptor function would predispose patients with DCM to cardiovascular events. The effect of polymorphisms in adrenergic receptor-related genes on cardiovascular event-free survival in patients with idiopathic DCM was evaluated. Methods and Results: Genotyping at 3 loci (ADRB1 Ser49Gly and Arg389Gly, and NET T-182C) was performed in 83 patients with DCM. Patients were followed prospectively to the endpoint of cardiovascular events (mean follow-up, 45 months). Cardiovascular events were defined as cardiac death and emergent hospitalization as a result of congestive heart failure, arrhythmia, and cerebrovascular events. Analyses were conducted based on the number of predicted risk genotypes a patient carried. The ADRB1 Ser49 allele carrier, ADRB1 Arg389 allele carrier, and NET-182CC genotype were defined as the predicted risk genotypes. Cardiovascular event-free survival was compared based on the number of predicted risk genotypes. Cardiovascular event-free survival was significantly better in patients with fewer than 3 predicted risk genotypes than in those with 3 predicted risk genotypes. Conclusions: Genotyping at these 3 loci might be a useful approach for identification of patients with DCM at risk for cardiovascular events. (Circ J 2012; 76: 2003–2008)
Heparin-binding epidermal growth factor-like growth factor (HB-EGF) is a cardiogenic and cardiohypertrophic growth factor. ProHB-EGF, a product of the Hb-egf gene and the precursor of HB-EGF, is ...anchored to the plasma membrane. Its ectodomain region is shed by a disintegrin and metalloproteases (ADAMs) when activated by various stimulations. It has been reported that an uncleavable mutant of Hb-egf, uc-Hb-egf, produces uc-proHB-EGF, which is not cleaved by ADAMs and causes dilation of the heart in knock-in mice. This suggests that the shedding of proHB-EGF is essential for the development and survival of cardiomyocytes: however, the molecular mechanism involved has remained unclear. In this study, we investigated the relationship between uc-proHB-EGF expression and cardiomyocyte survival. Human uc-proHB-EGF was adenovirally introduced into the rat cardiomyoblast cell line H9c2, and the cells were cultured under normoxic and hypoxic conditions. Uc-proHB-EGF-expressing H9c2 cells underwent apoptosis under normoxic conditions, which distinctly increased under hypoxic conditions. Furthermore, we observed an increased Caspase-3 activity, reactive oxygen species accumulation, and an increased c-Jun N-terminal kinase (JNK) activity in the uc-proHB-EGF-expressing H9c2 cells. Treatment of the uc-proHB-EGF transfectants with inhibitors of Caspase-3, reactive oxygen species, and JNK, namely, Z-VAD-fmk, N-acetylcysteine, and SP600125, respectively, significantly reduced hypoxic cell death. These data indicate that insufficiency of proHB-EGF shedding under hypoxic stress leads to cardiomyocyte apoptosis via Caspase-3- and JNK-dependent pathways.
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