Nariaki Kanemoto

Natural history of pulmonary hemodynamics in primary pulmonary hypertension

To study the relationship between the hemodynamic characteristics and prognosis in PPH, we analyzed the data on patients whose prognosis was well documented from the time of hemodynamic monitoring. Our subjects were 87 patients obtained from a nationwide survey in Japan. PCWPs were obtained in 44 patients and COs were measured in 59 patients. The average age was 33 years (range 14 to 69). Patients were followed prospectively for up to 100 months and were categorized based on the survival period from the time of catheterization. Hemodynamic variables that showed significant differences or prognostic trends were RVedp, pulmonary artery diastolic pressure, PCWP, CI, PVR, and PVR/SVR ratio. The CI correlated with the number of survival months (r = 0.583; p less than 0.01). The hemodynamic state of patients who died suddenly within 1 year from the time of catheterization was no different from those who died of clinical right-sided heart failure. The partial pressure of oxygen of arterial blood was the only variable discriminating sudden deaths from right-sided heart failure deaths (54 +/- 2 vs 66 +/- 4 mm Hg; p less than 0.05). The results of this study indicate that the major determinant of prognosis is right ventricular function and that the CI might be used as a prognostic indicator. In addition, sudden death is more likely to occur in patients with severe hypoxia.

Disappearing False Aneurysm of the Ventricular Septum Without Rupture: A Complication of Acute Inferior Myocardial Infarction—A Case Report

An interseptal false aneurysm of the left ventricle due to the dissection of the septum in a patient with acute inferior myocardial infarction is described. The aneurysm was demonstrated as a cystic bulge of the left ventricular cavity into the inferoposterior interventricular septum with a small orifice from the left ventricle without any protrusion or rupture into the right ventricular cavity. Two-dimensional echocardiography, magnetic resonance imaging, and dy namic computed tomography were the most useful and reliable noninvasive di agnostic modalities. Repeated examinations demonstrated a significant reduction of the aneu rysm in six months.

Electrocardiographic and Hemodynamic Correlations in Primary Pulmonary Hypertension

In order to evaluate the pulmonary hemodynamics in primary pulmonary hypertension, the relation between the standard 12-lead electrocardiogram (ECG) and pulmonary hemodynamics as determined by right-heart catheteriza tion was analyzed. Significant positive correlations were noted between ampli tude of the R in V1, the R/S ratio in V1, and the pulmonary artery systolic pressure (r=0.46 and 0.50, respectively, p < 0.01). An amplitude of the R in V1 of more than 1.2 mV indicated a pulmonary artery systolic pressure of more than 90 mmHg with a sensitivity of 94% and a specificity of 47%. The cardiac index showed a significant positive relationship with amplitude of the R in V5 and V6 and the R/S ratio in Vs and V6 (r = 0.46, 0.46, 0.39, and 0.48, respec tively ; each with a p < 0.01). Moreover, an ÂQRS ≥ 100°, and either an SV6 ≥ 0.7 mV, or R/SV 6 ≤ 2 indicated a cardiac index of < 2.8L/min/m2 with a sensitivity of 82% and 84% and a specificity of 86% and 100% respectively. This study suggests, therefore, that the 12-lead ECG is useful for the evalua tion of the severity of pulmonary hypertension by its ability to predict pulmo nary artery systolic pressure and cardiac index with clinically useful accuracy.

Evaluation of a nine-lead Holter monitor for identifying and localizing ischemia and coronary artery disease detected by quantitative thallium-201 tomography

We devised a nine-lead Holter monitor system with a lead-switching technique to record electrocardiograms from multiple sites in the anterior and the posterior or lateral chest. Leads CM1 to CM6, high lateral (HL), low lateral (LL), and low posterior chest (LB) were used. The sensitivity, specificity, and predictive accuracy of this system for identifying specific regions of myocardial ischemia and coronary artery disease were investigated in 130 patients with coronary artery disease. Anterolateral leads (CM4 to CM6, HL, and LL) showed high sensitivity for detecting anterior and lateral ischemia (69% to 100%) but low specificity (4% to 44%) compared with tomographic results. The specificity of these leads for identifying single-vessel disease was low (6% to 47%) although some leads showed high sensitivity (69% to 100%). In contrast, the LB lead exhibited high sensitivity and specificity for detecting inferior ischemia (70% and 95%, respectively) and right coronary artery (RCA) disease (74% and 93%, respectively). Consequently, ST depressions in the LB lead (anode) are specific for identifying inferior ischemia and RCA disease, whereas those in the anterior and lateral chest leads do not identify the ischemic region or the obstructed coronary artery.

Significance of U wave polarities in previous anterior myocardial infarction

The significance of the polarity of U waves in left precordial leads was evaluated in relation to myocardial perfusion (T1 201 myocardial scintigraphy) and left ventricular function (99m Tc radionuclide ventriculography) in 63 patients with clinical and electrocardiographic evidence of a previous anterior myocardial infarction. Patients were divided into three groups according to the polarity of the U waves: positive U waves, flat U waves, and negative U waves. Twelve matched patients served as normal controls. The following parameters were analyzed: (1) total number of abnormal Q waves; (2) total myocardial perfusion index and regional myocardial perfusion index; (3) global ejection fraction; (4) regional ejection fraction; and (5) number of diseased coronary arteries. The total myocardial perfusion index values were 43.9 +/- 1.0 in controls, 40.8 +/- 3.4 in the positive U wave group, 33.4 +/- 3.5 in the flat U wave group, and 30.3 +/- 4.4 in the patients with negative U waves. Global ejection fractions in these groups were, respectively, 63.9 +/- 8.6%, 65.0 +/- 11.8%, 53.6 +/- 8.1%, and 36.5 +/- 13.6%. The sensitivity of negative U waves suggesting a global ejection fraction of less than 45% was 91.6%, and the specificity was 82.1%. Therefore the size of myocardial infarction increased and left ventricular function decreased, in order, from patients with positive U waves, to those with flat U waves, to those with negative U waves, with statistically significant differences.(ABSTRACT TRUNCATED AT 250 WORDS)

A case of atrial dissociation.

A patient with brain tumor without cardiopulmonary abnormalities whose electrocardiogram revealed atrial dissociation is described. The rate of ectopic atrial rhythm was 207 beats/min and this rhythm was considered to originate from the superior, posterior and lateral portion of the left atrium.

Giant negative U waves in a patient with uncontrolled hypertension and severe hypokalemia.

A 66-year-old woman with a long history of hypertension had an electrocardiogram with giant negative U waves in left precordial leads despite hypokalemia. This seems to be the first report of giant negative U waves induced by uncontrolled hypertension with hypokalemia. The occurrence of negative U waves in the presence of profound hypokalemia is an important observation because it masks the electrocardiographic manifestation of hypokalemia.

Transient Reversal of Inverted U Waves During Valsalva's Test—A Case Report

The authors demonstrate for the first time that resting U wave inversion can become upright transiently during Valsalvas test.

Complete right bundle branch block (CRBBB) with three different mean frontal plane QRS axes--a case report.

A routine ECG of a seventy-year-old man, who had been followed for five years because of complete right bundle branch block (CRBBB) with first-degree atrioventricular (AV) block, showed CRBBB and three different mean frontal plane QRS axes suggesting normal conduction, bradycardia-dependent left anterior hemiblock, and tachycardia-dependent left posterior hemiblock—all within the same tracing. Holter recording demonstrated transient advanced AV block, and a permanent pacemaker was implanted.