Naoko Ishizuka

A noninvasive method of measuring wave intensity, a new hemodynamic index: application to the carotid artery in patients with mitral regurgitation before and after surgery

SummaryWave intensity (WI) is a new hemodynamic index, which is defined as (dP/dt)(dU/dt) at any site of the circulation, where dP/dt and dU/dt are the time derivatives of blood pressure and velocity, respectively. Arterial WI in normal subjects has two positive sharp peaks. The first peak occurs during early systole when a forward-traveling compression wave is generated by the left ventricle. The magnitude of this peak increases markedly with an increase in cardiac contractility. The second peak, which occurs towards the end of systole, is caused by generation of a forward-traveling expansion wave by the ability of the left ventricle to actively stop aortic blood flow. The interval between the R wave of the ECG and the first peak of WI (R-lst peak interval) and the interval between the first and second peaks (lst–2nd interval) are approximately equal to the preejection period and left ventricular ejection time, respectively. Using a combined Doppler and echotracking system, we obtained carotid arterial WI non-invasively. We examined the characteristics of WI in 11 patients with mitral regurgitation (MR) before and after surgery, and 24 normal volunteers. In the MR group before surgery, the second peak was decreased and the (lst–2nd interval)/(R-R interval) ratio was reduced, compared with the normal group (140 ± 130 vs 750 ± 290mmHgm/s3, P < 0.0083; 20.7% ± 3.4% vs 26.7% ± 2.8%, P < 0.0083). There were no significant differences in the first peak between the normal group and the MR group before and after surgery. The second peak in the MR group was increased significantly (P < 0,016 vs before surgery) to 1150 ± 830mmHgm/s3 in the early period after surgery (stage I), and to 1090 ± 580mmHgm/s3 in the late period after surgery (stage II). These values did not differ significantly from that of the normal group. At stage I, the (R-1st peak interval)/(R-R interval) ratio was increased from 13.4% ± 2.7% to 2.6% ± 5.6% (P < 0.016 vs before surgery). At stage II, this ratio decreased to 16.2% ± 2.8% (P < 0.016 vs stage I), but was still significantly higher than that before surgery. The (1st–2nd inteval)/(R-R interval) ratio increased significantly after surgery (P < 0.016 vs before surgery) to values (27.0% ± 4.5% at stage I and 28.9% ± 2.6% at stage II) which did not differ significantly from that of the normal group. The recovery of the second peak after surgery suggests that the left ventricle had recovered the ability to actively stop aortic blood flow. Wave intensity is useful for analyzing changes in the working condition of the heart.

Echocardiographic findings and clinical features of left ventricular pseudoaneurysm after mitral valve replacement

We studied the echocardiographic findings and clinical features of left ventricular pseudoaneurysm after mitral valve replacement. From December 1979 to March 1991, 1050 patients underwent mitral valve replacement at our institute, and eight patients (0.8%) had left ventricular pseudoaneurysm. In all eight patients, left ventricular pseudoaneurysm developed after the second mitral valve replacement. The incidence of left ventricular pseudoaneurysm among 253 patients who had had previous mitral valve surgery was 3.1%. Seven of the eight patients were still alive and were followed up from 5 to 136 months (mean, 57 months) after the development of left ventricular pseudoaneurysm; these patients had no complications. One patient died as a result of low cardiac output after mitral valve replacement in spite of repair of the left ventricular pseudoaneurysm. This patient had a long and wide myocardial laceration near the left ventricular pseudoaneurysm. In the other seven patients, transthoracic echocardiography demonstrated a large extraventricular cavity along the posterobasal left ventricle. In five of these patients, a turbulent flow in the neck of the left ventricular pseudoaneurysm was recorded both in systole and diastole by pulsed and color Doppler echocardiography. Transesophageal echocardiography clearly showed the narrow neck of the left ventricular pseudoaneurysm and an abnormal flow between the left ventricle and the left ventricular pseudoaneurysm. Generally, when left ventricular pseudoaneurysm develops after mitral valve replacement, surgical repair is the first choice of therapy. Our study demonstrated, however, that the development of left ventricular pseudoaneurysm was not always associated with a poor prognosis without surgical intervention.(ABSTRACT TRUNCATED AT 250 WORDS)

Single administration of cerivastatin, an HMG-CoA reductase inhibitor, improves the coronary flow velocity reserve: a transthoracic Doppler echocardiography study

HMG-CoA reductase inhibitors (statins) have been shown to improve the endothelial function by lowering lipids. Recent studies also suggest a direct impact of statins on the vascular wall. We assessed the rapid effect of cerivastatin on the coronary flow velocity reserve (CFVR) using transthoracic Doppler echocardiography (TTDE). The coronary flow velocity from the distal left anterior descending artery was measured in 16 healthy subjects (all male, age 24–38 years) using a 5-MHz transducer, on the day before, just before, and 3 h after administering 0.3 mg of cerivastatin. Hyperemia was achieved by the intravenous administration of adenosine, and the CFVR was calculated as the radio of the mean diastolic hyperemic coronary flow velocity to the basal flow velocity. The serum lipid profile and high-sensitivity C-reactive protein (hsCRP) were measured. The CFVR following the single administration of cerivastatin increased from 2.93 ± 0.58 to 3.91 ± 0.86, P = 0.003, and was significantly higher than the CFVR measured at the same time on the previous day (3.91 ± 0.86 vs 3.37 ± 0.48, P = 0.009). Neither the serum lipid profile nor hsCRP exhibited a remarkable change after cerivastatin administration. We concluded that a single-dose administration of cerivastatin, an HMG-CoA reductase inhibitor, improves the coronary flow velocity reserve without modifying the serum lipid profile.

Accessory mitral valve tissue causing severe left ventricular outflow tract obstruction in an adult

Accessory mitral valve (AMV) is a rare cause of left ventricular outflow tract (LVOT) obstruction and is extremely rare in adults. We report a case of an older adult with an AMV that caused severe LVOT obstruction. A parachute-like piece of tissue (the AMV) protruding into the LVOT during systole was first detected in a 45-year-old woman by echocardiography. Because the pressure gradient and dyspnea gradually progressed, she finally underwent a successful operation for removal when she was 48 years old.

Subepicardial aneurysm after anticoagulant therapy for a mural thrombus following anterior myocardial infarction

Abstract A subepicardial aneurysm became evident in a male patient after anticoagulant therapy. On admission, it appeared to be an old anterior infarction accompanied by a mural thrombus. After warfarin administration, the thrombus disappeared and an echo-free space emerged outside the apical myocardial wall. The echo-free space communicated with the left ventricular cavity through the apical myocardial wall. Emergency surgery was undertaken and the patient survived. The aneurysm was covered with epicardium and there was an endomyocardial rupture of the muscle in the apical wall, which was the entrance of the aneurysm. This case suggests that cautious follow-up with echocardiography is necessary when anticoagulant therapy is selected for thrombi following myocardial infarction.

Plasma brain natriuretic peptide as a parameter to assess efficacy of continuous intravenous infusion of prostacyclin (epoprostenol) to treat severe primary pulmonary hypertension: a case report

Abstract Continuous intravenous infusion of prostacyclin (epoprostenol) as a treatment for primary pulmonary hypertension (PPH) definitely improves the patients quality of life, but few accurate parameters have been found to evaluate the efficacy of the treatment. We observed a patient with severe PPH whose plasma brain natriuretic peptide (BNP) level changed significantly as her condition and symptoms changed. Plasma BNP may be considered as one of the parameters for assessing the efficacy of prostacyclin treatment.

Extremely Rapid Formation of Mitral Valve Ring Abscess in Infective Endocarditis

A patient with infective endocarditis (IE) due to methicillin‐resistant staphylococcus aureus (MRSA) was found to have conversion of the hypoechoic region of the posterior mitral valve ring apparatus into a clearly delineated echolucent space by repeating transthoracic echocardiography at an interval of 1 week. Color Doppler showed features of blood entry into this space. Abscess formation in IE due to MRSA may be quick and repeated echocardiography may help detect the complications of IE. Semiurgent mitral valve plasty was performed for the associated prolapse of the posterior mitral leaflet using a hand‐made, rolled, twisted autologous pericardial ring.

Gender Differences in Predictors of Left Ventricular Myocardial Relaxation in Non-Obese, Healthy Individuals

Background Previous studies indicate that individuals with metabolic syndrome (MetS) might be at risk for left ventricular (LV) diastolic dysfunction. However, little is known about which metabolic factors contribute to the development of LV dysfunction in individuals who are not obese or overweight and who do not have diabetes mellitus and/or cardiovascular disease. Methods Participants without diabetes mellitus, systolic dysfunction, or other heart diseases underwent a thorough physical examination, including tissue Doppler echocardiography. A peak early mitral annular velocity (e′) of <5.0 was designated as indicating abnormal LV myocardial relaxation (LVMR). We performed single and multiple logistic regression analyses of e′ and cardiovascular risk factors, including MetS factors and indicators of major organ dysfunction. Normal-weight subjects (body mass index <25 kg/m2) were also analyzed. Results A total of 1055 individuals (mean age, 63 ± 13 years) participated, of which 307 (29.1%) had MetS and 199 (18.9%) had abnormal LVMR. Multiple logistic regression analysis revealed waist circumference (WC) (odds ratio [OR] 1.04, P < 0.05) and age (OR 1.10, P < 0.05) to be predictors of abnormal LVMR. In normal-weight subjects (n = 806), aging (OR 1.08, P < 0.01), abnormal WC (OR 3.80, P < 0.01), and renal dysfunction (OR 2.14, P < 0.01) were predictors of abnormal LVMR. Among MetS factors, abnormal WC in men (OR 3.70, P < 0.01) and high diastolic blood pressure (DBP) in women (OR 4.00, P = 0.01) were related to abnormal LVMR.

Echocardiographically evaluated site of attachment of atrial myxoma may predict recurrence

We explore the association between the site of attachment of nonfamilial left atrial myxoma and it’s recurrence. Forty-three (11 male and 32 female; mean age, 55.9±13.6 years) of 49 consecutive patients with nonfamilial left atrial myxoma who had been evaluated with preoperative echocardiography, X were available for postoperative follow-up with transthoracic echocardiography, transesophageal echocardiography, or both, for an average period of 85.2±54.2 months (range, 6.5 to 215.5 months). We compared preoperative clinical and echocardiographic features of recurrent and nonrecurrent myxomas. Three (7%) of the 43 cases of atrial myxoma recurred at the same site after 24.1±7.6 months. Involvement of the mitral valve annulus or mitral valve leaflet (3 vs 0,p<0.001) was observed in the recurrent myxomas, but the two groups did not differ significantly in any other clinical features, laboratory data, or echocardiographic features of the recurrent and nonrecurrent myxoma. Preoperative echocardiographic observation of involvement of the mitral valve annulus or mitral valve leaflet may predict recurrence after surgery. Regular follow-up echocardiography was useful in the early detection of recurrence.