Transient receptor potential vanilloid 1-expressing cardiac afferent nerves may contribute to cardiac hypertrophy in accompany with an increased expression of brain-derived neurotrophic factor within nucleus tractus solitarius in a pressure overload model.

INTRODUCTION: Increased sympathetic output contributes to cardiac hypertrophy. Sympathoexcitation is induced by activating the cardiac sympathetic afferent nerves through transient receptor potential vanilloid 1 (TRPV1) in cardiac afferent endings. Brainstem nucleus tractus solitarius (NTS) receives the sensory cardiac afferent inputs. Brain-derived neurotrophic factor (BDNF) is released within NTS from sensory neurons in an activity-dependent manner. Additionally, BDNF in NTS tonically regulates sympathetic activity. Therefore, we hypothesized that TRPV1-expressing cardiac afferent nerves contribute to cardiac hypertrophy in accompany with an increased BDNF expression in NTS. METHODS AND RESULTS: Abdominal aortic banding (AB) or sham operation was conducted in wild-type C57BL/6 J (WT-AB) and TRPV1 knockout mice (TRPV1 KO-AB). At 8 weeks post-operation, echocardiographic left ventricular wall thickness and heart weight/body weight ratio were significantly greater in WT-AB than WT-Sham mice, and these hypertrophic indexes were attenuated in TRPV1 KO-AB mice. Among the groups, left ventricular fractional shortening was not different. The protein levels of TRPV1 in heart and BDNF in NTS were significantly increased in WT-AB compared to WT-Sham mice, whereas BDNF expression in NTS was not increased by AB in TRPV1-KO mice. Chemical ablation of TRPV1-expressing cardiac afferents attenuated the AB-induced cardiac hypertrophy and increase in BDNF in NTS. Sympathetic activity analyzed using heart rate variability, and sympathoexcitatory responses to the stimulation of cardiac afferents were increased in WT-AB compared to WT-Sham mice. CONCLUSION: TRPV1-expressing cardiac afferent nerves may contribute to pressure overload-induced cardiac hypertrophy in accompany with the increased BDNF within NTS.

Statistical Analysis of Dual-task Gait Characteristics for Cognitive Score Estimation.

Traditional approaches for the screening of cognitive function are often based on paper tests, such as Mini-Mental State Examination (MMSE), that evaluate the degree of cognitive impairment and provide a score of patient's mental ability. Procedures for conducting paper tests require time investment involving a questioner and not suitable to be carried out frequently. Previous studies showed that dementia impaired patients are not capable of multi-tasking efficiently. Based on this observation an automated system utilizing Kinect device for collecting primarily patient's gait data who carry out locomotion and calculus tasks individually (i.e., single-tasks) and then simultaneously (i.e., dual-task) was introduced. We installed this system in three elderly facilities and collected 10,833 behavior data from 90 subjects. We conducted analyses of the acquired information extracting 12 features of single- and dual-task performance developed a method for automatic dementia score estimation to investigate determined which characteristics are the most important. In result, a machine learning algorithm using single and dual-task performance classified subjects with an MMSE score of 23 or lower with a recall 0.753 and a specificity 0.799. We found the gait characteristics were important features in the score estimation, and referring to both single and dual-task features was effective.

Prior exposure to placental ischemia causes increased salt sensitivity of blood pressure via vasopressin production and secretion in postpartum rats.

OBJECTIVES: Women with a history of preeclampsia exhibit increased salt sensitivity of blood pressure at postpartum, which might be responsible for their increased risk of future cardiovascular diseases. However, it is unclear whether preeclampsia can cause increased salt sensitivity at postpartum. Vasopressin may play a role in the pathogenesis of preeclampsia and salt-sensitive hypertension. Therefore, the aim of this study was to determine whether the exposure to preeclampsia, as elicited by placental ischemia, causes increased salt sensitivity at postpartum, and if so, whether vasopressin is involved in its process. METHODS AND RESULTS: We used a reduced uterine perfusion pressure (RUPP) rat model of preeclampsia. Pregnant Sprague-Dawley rats were categorized into the following two groups: RUPP-operated and sham-operated (SHAM) control groups. A 1-week-long high-salt diet was initiated at 3 weeks postpartum. The high-salt diet-induced increase in mean arterial pressure was significantly greater in the RUPP group than in the SHAM group. In addition, the plasma levels of copeptin, a substitute for plasma vasopressin, increased and serum osmolality decreased in the RUPP group. Double immunostaining revealed that the expression of c-Fos, a marker of neural activity, in vasopressin-producing neurons and presympathetic neurons in the hypothalamic paraventricular nucleus was significantly elevated in the RUPP group. The oral administration of conivaptan, the dual V1a/V2 vasopressin receptor antagonist, during high-salt diet abolished the enhanced increase in mean arterial pressure in RUPP rats. CONCLUSION: Prior exposure to placental ischemia causes increased salt sensitivity of blood pressure at postpartum probably due to enhanced vasopressin production and secretion.

Coronary Artery Disease Screening With Carotid Ultrasound Examination by a Primary Care Physician.

BACKGROUND: In this study, we investigated the feasibility of primary care physicians using carotid ultrasound to perform coronary artery disease screening in asymptomatic patients with multiple coronary risk factors. METHODS: We retrospectively collected the data of 135 consecutive asymptomatic patients (mean age: 68.5 ± 8.4 years; male, 75%) who were referred to our institution due to abnormal findings on a carotid ultrasound performed by a primary care physician and who underwent coronary computed tomography angiography. RESULTS: The mean number of risk factors was 4.1 ± 1.2 and the mean intima-media thickness was 2.00 ± 0.63 mm. Mild (≤ 50%), moderate (51-75%), and severe (> 76%) coronary stenosis was observed in 54 (40%), 27 (20%), and 25 patients (19%), respectively, while no plaque was found in 24 patients (18%), and five patients (4%) could not be evaluated due to calcification. Consequently, coronary angiography was performed in 56 (41%) patients and coronary intervention was required in 31 patients (23%). A multivariate logistic regression analysis demonstrated that the ratio of low-density lipoprotein cholesterol levels to high-density lipoprotein cholesterol levels, the use of calcium channel blockers and the value of the diastolic blood pressure were related to > 50% coronary stenosis. CONCLUSIONS: The use of carotid ultrasound in the coronary artery disease screening by primary care physicians resulted in a high prevalence of coronary artery disease and high probabilities of coronary angiography and revascularization, and thus it is considered to be a useful and feasible strategy for the screening of asymptomatic patients.

Blackout during meals: A case report of swallow syncope due to sinus arrest.

A 79-year-old male, with a history of percutaneous coronary intervention (PCI), was referred to our cardiovascular department for a detailed examination of blackout caused by sinus arrest only during meals. Ultrasound echocardiography showed normal cardiac contraction with no asynergy, irrespective of the remaining stenotic coronary lesion. An electrophysiological study revealed deteriorated atrioventricular nodal conduction at a Wenckebach point of 70 beats per minute. However, sinus node function was normal as demonstrated by a sinus node recovery time of 1369 ms. Coronary angiography showed triple-vessel disease including the remaining stenotic coronary lesion, and a PCI was performed on the right coronary artery. Nevertheless, sinus arrest during meals was unchanged. Swallow syncope was partially improved by dietary modification; however, pacemaker implantation (PMI) was performed eventually, and the patient became asymptomatic after PMI. .

Resolution of a left ventricular thrombus by the thrombolytic action of dabigatran.

A 77-year-old man was referred to our cardiovascular department for detailed examination after abnormal electrocardiography findings were obtained during a preoperative cataract surgery workup. Ultrasound echocardiography (UCG) and computed tomography (CT) revealed evidence of previous myocardial infarction with anteroseptal akinesis and a left ventricular (LV) thrombus (14 × 12 mm). Dabigatran (220 mg/day) was prescribed as an outpatient treatment, and the disappearance of the LV thrombus was confirmed by UCG and CT 27 days after dabigatran initiation. No thromboembolism occurred between treatment initiation and thrombus resolution. Our results indicate that dabigatran has thrombolytic action on an acute pre-existing intracardiac thrombus.

Ventricular pacing inhibition by oversensing due to diaphragmatic myopotential during deep inspiration.

An 80-year-old man, who had dilated cardiomyopathy with right ventricular (RV) dilatation, underwent implantable cardioverter defibrillator (ICD) implantation for advanced atrioventricular block and primary prevention of sudden cardiac death. Tined and screw-in leads were placed on the right atrial appendage and RV apex, respectively. Ventricular pacing inhibition was detected after surgery due to oversensing by diaphragmatic myopotential occurring only during deep inspiration. We performed re-surgery and switched the screw-in lead for a tined lead. The diaphragmatic myopotential decreased, thereby improving oversensing by diaphragmatic myopotential and ventricular pacing inhibition. It might be beneficial to use a tined lead when placing the ventricular lead at the RV apex for implantation of a pacemaker or ICD if oversensing of diaphragmatic myopotential is observed using a screw-in lead. .