Mid-ventricular obstruction: A variant of obstructive cardiomyopathy

here are 2 types of hypertrophic obstructive cardiomyopathy (HOCM): obstruction at the subaorta, called idiopathic hypertrophic subaortic stenosis (IHSS), 1 and obstruction at the mid left ventricle. 2 In contrast to the many studies of IHSS, only a few studies, other than case reports, have focused on midventricular obstruction (MVO). Two patients with MVO were reported for the first time in 1976 by Falicov et al, 2 one of whom suddenly died shortly after unsuccessful myectomy. Maron et al elucidated that the left ventricular pressure gradient (LVPG) was related to even prognosis in patients with hypertrophic cardiomyopathy (HCM). 3 Thus, attenuation of the LVPG has recently become an important strategy in the management of patients with HOCM.In the clinical setting, patients with MVO may often be overlooked. Very recently we reported that there are 2 specific patterns of carotid pulse tracing in these patients, 4 by which they may be diagnosed with ease. As to the treatment of patients with MVO, Hintringer et al reported the usefulness of permanent DDD pacing to alleviate LVPG and symptoms in an 85-year-old woman with MVO who did not respond to pharmacological therapy. 5 In patients with MVO, unlike those with IHSS, therapies involving myotomy or myectomy and alcohol septal ablation require great caution to prevent the induction or deterioration of mitral regurgitation. Both -blockers and calcium antagonists are often insufficient for attenuating LVPG. In 1982, Pollick reported the usefulness of the antiarrhythmic drug disopyramide in attenuating LVPG in IHSS. 6 Unfortunately sustained use of disopyramide is difficult owing to the thirst, dysuria and so on related to its strong anticholinergic action. We previously reported the usefulness of the antiarrhythmic drug, cibenzoline, the anticholinergic action of which is very weak, 7 to attenuate LVPG in IHSS. 8 In the present study, therefore, we examined the acute and chronic effect of cibenzoline on LVPG and left ventricular (LV) diastolic dysfunction in patients with MVO. Methods Study SubjectsTwenty-three patients with MVO participated in this study after giving written informed consent. Twenty healthy control subjects served as the comparison of the hemo-

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confidence: 99%

Antiarrhythmic Drug Cibenzoline Attenuates Left Ventricular Pressure Gradient and Improves Transmitral Doppler Flow Pattern in Patients With Hypertrophic Obstructive Cardiomyopathy Caused by Midventricular Obstruction

Hamada

Shigematsu

Inaba

et al. 2005

“…8,10 Therefore, relief of the high apical pressure may be necessary to preventing further asynergy. It has been considered that drug-refractory patients with MVO are candidates for cardiac surgery, 11,12 but recently, pacing therapy for pressure gradient reduction in patients with MVO has been reported, 6 as is the case for patients with hypertrophic LVOT obstruction. [1][2][3][4][5] Previous reports have suggested that the paradoxical motion of the interventricular septum may play a role in the relief of LVOT obstruction, [1][2][3][4][5] and another study has indicated that pacing reduces septal wall motion in patients with LVOT obstruction.…”

Section: Discussionmentioning

confidence: 99%

Beneficial Effect of Dual-Chamber Pacing for a Left Mid-Ventricular Obstruction With Apical Aneurysm.

Watanabe

Kibira

Saito

et al. 2002

t has been well established that dual-chamber pacing reduces the pressure gradients in the left ventricular outflow tract (LVOT) and improves the symptoms of hypertrophic obstructive cardiomyopathy. [1][2][3][4][5] However, the effect of pacing therapy on a hypertrophic mid-ventricular obstruction (MVO) with an apical aneurysm has rarely been described 6 and we report such a case that was dramatically improved by dual-chamber pacing.This report is of special interest from 2 points of view. We demonstrate, on the basis of this case, that the pacing therapy was effective in not only reducing intraventricular pressure gradient, but also in preventing sustained ventricular tachycardia (VT). Secondly, we are the first to attempt to evaluate the intraventricular flow dynamics during pacing in such a case. Case ReportA 63-year-old woman suffered chest discomfort with a syncope attack and was admitted to hospital. Her past history and familial history were unremarkable. The 12-lead electrocardiogram (ECG) on admission showed sustained monomorphic VT (170 beats/min) with a right bundle branch block pattern in V1 and a QS pattern in leads I, II, III, aVF and V2-6, and an axis of -140°. These findings were Circulation Journal Vol.66, October 2002 similar to those seen with VT originating from the septoapical area of the left ventricle (Fig 1). 7 After spontaneous recovery to sinus rhythm 40 s later, the ECG showed negative T waves in leads I, II, III, aVF and V1-6 with slight ST elevation in III, aVF and V4 (Fig 1). Holter monitoring showed 2 episodes of sustained monomorphic VT (30-40 s), 1,220 episodes of nonsustained monomorphic VT and 355 episodes of couplet ventricular extrasystoles per day. Although a -blocking agent is the drug of choice, it did not completely suppress the VT. The 2-dimensional echocardiographic examination revealed left mid-ventricular hypertrophy at the papillary muscle level and a discrete Invasive assessment of intraventricular pressure showed a peak-to-peak gradient greater than 100 mmHg. Treatment with antiarrhythmic agents could not prevent the VT, but dual-chamber pacing reduced the intraventricular pressure gradient and suppressed the VT completely. Continuous wave Doppler showed that the early systolic ejection flow from the apex had disappeared, that there was isovolumetric relaxation flow toward the apex and that there was attenuation of the diastolic paradoxical jet flow toward the basal chamber. Such findings by continuous wave Doppler can be useful in pacing therapy for evaluating changes in the severity of mid-ventricular obstruction. (Circ J 2002; 66: 981 -984)

“…[8][9][10] Subsequently, mid-ventricular obstruction (left ventricular cavitary obliteration) has been found in other diseases; for example, a case of apical myocardial infarction with hyperdynamic contraction of the mid and basal portion of the left ventricle and a case of severe concentric left ventricular hypertrophy. 12,13 Moreover, this phenomenon can be produced in patients undergoing dobutamine stress echocardiography and even in subjects with normal left ventricles with loading conditions manipulated by the Valsalva maneuver after the administration of amyl nitrate.…”

Section: Discussionmentioning

confidence: 99%

“…[1][2][3][4][5][6][7] Initially, mid-ventricular obstruction had been reported as a special form of hypertrophic cardiomyopathy, but it can be found in other conditions such as myocardial infarction, hypertensive heart disease, and even in normal subjects with alternation of loading conditions. [8][9][10][11][12][13] We report a case of shoshin beriberi and mid-ventricular obstruction of the left ventricle with an apical aneurysm. The patient's left ventricular wall thickness was not hypertrophic, and the aneurysmal site was perfused by the left anterior descending artery, in which spasm was provoked using acetylcholine.…”

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confidence: 95%

Shoshin Beriberi With Vasospastic Angina Pectoris. Possible Mechanism of Mid-Ventricular Obstruction.

Ito

Tanabe

Suzuki

et al. 2002

eriberi heart is a very rare disease today and is caused by thiamin deficiency. 1 Beriberi heart is hemodynamically characterized by high cardiac output failure associated with arteriolar vasodilatation. Shoshin beriberi is a fulminant form of beriberi heart and is characterized by hypotension, tachycardia, and lactic acidosis. [1][2][3][4][5][6][7] Initially, mid-ventricular obstruction had been reported as a special form of hypertrophic cardiomyopathy, but it can be found in other conditions such as myocardial infarction, hypertensive heart disease, and even in normal subjects with alternation of loading conditions. [8][9][10][11][12][13] We report a case of shoshin beriberi and mid-ventricular obstruction of the left ventricle with an apical aneurysm. The patient's left ventricular wall thickness was not hypertrophic, and the aneurysmal site was perfused by the left anterior descending artery, in which spasm was provoked using acetylcholine. Case ReportA 73-year-old man was admitted to hospital suffering from chest pain and adynamia of the limbs. He had a history of inferior myocardial infarction, which was followed by conventional therapy when he was aged 65 years. Thereafter, he frequently experienced angina at rest, especially at night. He was a heavy drinker from his young days and he drank to overcome his anginal chest pain instead of taking medication. His alcohol intake had increased gradually, and he had stopped eating completely and been drinking all day for 1 month prior to admission. His blood pressure on admission was 68/30 mmHg and he was in a state of shock. His first and second heart sounds were normal and, although hepatomegaly was present, bilateral pitting edema was not. The power of his inferior limbs was very weak and his deep tendon reflex had disappeared.An electrocardiogram showed sinus tachycardia with a heart rate of 120 beats/min, and ST depression in leads I, II, III, aVF, and V1-V6, as well as negative T waves in leads II, III, and V1-V3. Echocardiography demonstrated hyperkinesis of the left ventricle and mid-ventricular obstruction with a peak intraventricular pressure gradient of 30 mmHg, but his left ventricular wall thickness was not hypertrophic. Laboratory data were normal except for a slight increase in creatine kinase (CK) (223 IU/L). After administering 3 L/min of oxygen, arterial blood gases revealed a pH of 7.27, pO2 105 mmHg, and pCO2 17 mmHg.Despite massive intravenous administration of catecholamine (dopamine 20 g·min -1 ·kg -1 , dobutamine 20 g·min -1 · kg -1 , and noradrenaline 0.2 g·min -1 ·kg -1 ), his blood pressure did not increase. Despite his state of shock, cardiac output was increased markedly and systemic vascular resistance was extraordinarily low. From his hemodynamic data (Table 1), shoshin beriberi was suspected and 100 mg of thiamin was administered intravenously, resulting in the patient's condition improving quickly (Table 1); however, peripheral blood concentration of vitamin B1, which was obtained after intravenous administration of 10 mg of thiam...