Effect of left ventricular (LV) volume on right ventricular (RV) end-systolic pressure-volume relation (ESPVR) was investigated, and the mechanism was examined from a standpoint of the alteration of RV free wall mean fiber length. Twelve cross-circulated isovolumically contracting canine hearts in which both ventricular volumes were controlled independently were used, and RV-ESPVR was determined at three different LV volume levels. At small (10.2 +/- 0.6 ml), middle (15.3 +/- 1.0 ml), and large (20.5 +/- 1.4 ml) LV volume, the slope of the RV-ESPVR was 2.63 +/- 0.13, 2.74 +/- 0.13, and 2.89 +/- 0.12 mm Hg/ml, respectively, and each value was significantly different from the others (p less than 0.01). The volume intercept (V0) of the relation (RV-V0) was significantly decreased with the increment of LV volume (RV-V0 in small, middle, and large LV volume; 3.92 +/- 0.68, 3.39 +/- 0.67, and 2.87 +/- 0.71 ml, respectively; p less than 0.01). In nine hearts, RV free wall lengths in latitudinal and meridional direction were measured at three LV volume levels when RV volume was held constant (16.1 +/- 1.1 ml). RV latitudinal end-diastolic length was significantly augmented with increasing LV volume (latitudinal length in small, middle, and large LV volume; 9.68 +/- 0.55, 9.81 +/- 0.56, and 9.92 +/- 0.55 mm, respectively). RV meridional end-diastolic length also increased significantly with increasing LV volume.(ABSTRACT TRUNCATED AT 250 WORDS)
Abstract:We herein report a case of hemichorea-hemiballism in an 85-year-old man diagnosed with diabetes at 76 years of age. After a one-year interruption in treatment, he was treated with a low-calorie diet, linagliptin, and nateglinide. Over 51 days, his HbA1c level decreased from 15.8% to 7.7%. After a prompt improvement in his hyperglycemia, he began experiencing involuntary movements in the right upper and lower extremities. T1-weighted magnetic resonance imaging showed a high signal intensity in the left lens nucleus. The patient was diagnosed with diabetic hemichorea-hemiballism and received haloperidol (1 mg/day) as treatment.
The diastolic and systolic pressure of one ventricle is increased by an increase in volume and/or pressure of the opposite ventricle; however, a mechanism for the ventricular interaction remains unclear. We hypothesized that the shape change of one ventricle elicited by the opposite ventricle would lead to resetting of the regional length, which may explain the ventricular interaction. We used 15 cross-circulated isovolumically contracting canine hearts in which both ventricular volumes were independently controlled. Diastolic regional segment area was calculated by multiplying circumferential and longitudinal lengths on right ventricular free wall (RVFW; n = 6), interventricular septum (IVS; n = 11), and left ventricular (LV) FW (n = 12). The regional area at relatively small volumes of both ventricles were expressed as 100%. With constant RV volume, increasing LV from 7 to 19 ml increased RV diastolic and systolic pressures by 2.7 and 5.5 mmHg, respectively. Conversely, increasing RV volume increased LV diastolic and systolic pressures by 2.3 and 7.5 mmHg, respectively. Increasing LV volume increased RVFW regional area from 121.0 to 124.6% (P < 0.01) and increased IVS regional area from 103.3 to 108.7% (P < 0.01), whereas the RV volume was held constant. Increasing RV volume also increased LVFW and IVS regional areas from 109.9 to 111.6% (P < 0.01) and from 106.8 to 108.9% (P < 0.05), respectively. Ventricular shape change elicited by ventricular interaction will increase the regional wall area, even though the volume of the chamber is unchanged. The increase in the regional area alters the position of the tissue on its resting and active length-tension relations and, thus, leads to enhancement of the chamber pressure.
Herein, we report on an 82-year-old woman who presented with anorexia. The patient had hyponatremia with preserved urinary osmotic pressure. T1-weighted magnetic resonance imaging (MRI) showed a lack of high signal intensity (SI) in the posterior pituitary lobe. Based on the patient's high levels of N-terminal prohormone of brain natriuretic peptide (NT-proBNP), heart failure was suspected. The heart failure may have caused arginine vasopressin (AVP) secretion. The depletion of AVP secretory granules may therefore cause the posterior pituitary gland to disappear on T1-weighted MRI.
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