Beneficial Effect of Cibenzoline on Left Ventricular Pressure Gradient With Sigmoid Septum

Abstract

sigmoid-shaped ventricular septum is one of the causes of left ventricular outflow tract (LVOT) obstruction in older patients and because it is rarely related to clinical symptoms, 1,2 medical therapy for the reduction of the left ventricular pressure gradient (LVPG) associated with sigmoid septum has not been established. It was recently reported that the class Ia antiarrhythmic drug, cibenzoline, attenuates the LVPG in patients with hypertrophic obstructive cardiomyopathy (HOCM), 3 and we describe a patient with LVPG caused by a sigmoid-shaped septum who improved after administration of cibenzoline. Case ReportA 83-year-old-female was admitted to hospital with episodes of dyspnea on effort after having breakfast. She had had hypertension for 20 years prior to admission. Her blood pressure was 154/74 mmHg, and her pulse rate was 100 beats/min and regular. Her physical examination was unremarkable, except for a grade 4/6 systolic murmur at the left sternal border in the third to fourth intercostal space. Routine blood tests were normal except for brain natriuretic peptide (BNP) of 455 pg/ml. An electrocardiography recorded 18 years prior to admission had been normal, whereas that recorded in the current admission showed normal sinus rhythm at a rate of 75 beats/min and left ventricular hypertrophy with ST-segment depression and inverted T waves characteristic of the strain pattern (Fig 1). Chest X-ray showed cardiomegaly with a cardiothoracic ratio of 56%. Two-dimensional transthoracic echocardiography revealed a sigmoid-shaped base of the interventricular septum markedly protruding into the left ventricle and calcification of both posterior mitral leaflet and aortic valve (Fig 2A,B), whereas that performed 18 years prior to admission had been normal (Fig 3). The remainder of the septum and the left ventricular free wall were concentrically hypertrophied, but no enlargement of the left ventricular cavity was observed. The angle between the mid line axis of the ascending aorta and that of the interventricular septum was 97.5°(normal range, 145±7°). M-mode echocardiography demonstrated a systolic anterior motion of the mitral valve (SAM) with fractional shortening (FS) of 39% ( Fig 4A). Color Doppler echocardiography showed turbulent systolic flow through the LVOT with a pressure gradient of 121.8 mmHg, mild aortic stenosis, and moderate mitral regurgitation (Figs 2C,4B). Cardiac catheterization was performed and angiography indicated an intermediate stenosis in the mid portion of the right coronary artery. The left ventricular end-diastolic pressure was 18 mmHg and the peak-to peak LVPG at the LVOT was 146 mmHg. These findings confirmed the diagnosis of LVOT obstruction caused by the sigmoid septum, concentric left ventricular hypertrophy and SAM.To reduce the LVOT obstruction, 60 mg/day of metoprolol was administered, but despite that treatment the LVPG remained at approximately 100 mmHg. Hence, 200 mg/day of cibenzoline, a class Ia antiarrhythmic agent, was administered in addition to 40 mg/day of metoprolol. A...

Effect of Cibenzoline and Atenolol Administration on Dynamic Left Ventricular Obstruction Due to Sigmoid-Shaped Septum

“…12,13 Recently, in clinical case of SS with LVH due to HT, the satisfactory result of improving LVPG using cibenzoline in addition to metoprolol was demonstrated. 4 In our 2 cases without LVH, dual therapy with cibenzoline and atenolol obviously improved the LVPG caused by exercise in contrast to monotherapy with atenolol. Therefore, we consider that the combined therapy of cibenzoline and a -blocker may exert a more beneficial effect than a -blocker alone.…”

“…7,8 However, several reports have demonstrated that SS sometimes causes significant narrowing of the LVOT, particularly in cases of LVH or acute myocardial infarction, or when it is exposed to exercise load, anesthesia or surgery. [1][2][3][4][5][6] Furthermore, it has been reported that dehydration, eating, antihypertensive drugs with vasodilating action and positive inotropic agents may increase the LVPG in some cases with SS as well as in those with HOCM. 11 When the dynamic left ventricular obstruction affects the clinical conditions in cases of SS, hypercontraction of left ventricle as well as narrowing of the LVOT are necessary.…”

Delayed-Onset Systolic Anterior Motion of the Mitral Valve After Aortic Valve Replacement for Severe Aortic Stenosis

“…[11][12][13][14] Cibenzoline is a strong Na + channel-blocking TREATING DELAYED SAM AFTER AVR WITH CIBENZOLINE agent, which promotes a decrease in the intracellular Ca 2+ concentration of cardiac myocytes 15) and has a Ca 2+ channel blocking action. Konishi, et al 16) described a similar effect of cibenzoline injection on the left ventricular pressure gradient in a patient with a sigmoid septum.…”

Dynamic Intraventricular Obstruction in Acute Myocardial Infarction With Administration of Cilostazol

“…Sigmoid septum is usually considered as a normal part of the aging process that is of little clinical importance, but several cases associated with outflow obstruction have been reported. [12][13][14][15] During the subacute phase of AMI in which there was a disappearance of the systolic murmur, provocation with dobutamine caused a 30 mmHg pressure gradient between the apex and LVOT in this case. This phenomenon might be caused by the sigmoid septum as previously described.…”