Dynamic Left Ventricular Outflow Tract Obstruction in the Setting of Acute Anterior Myocardial Infarction: A Serious and Potentially Fatal Complication?

Abstract

Dynamic left ventricular outflow tract (LVOT) obstruction was thought to be a hallmark of hypertrophic obstructive cardiomyopathy, especially in those cases with isolated asymmetric septal hypertrophy and systolic anterior motion (SAM) of the mitral valve. Recently, several authors described the occurrence of a dynamic LVOT obstruction during acute coronary insufficiency in ventricles without significant myocardial hypertrophy. The LVOT gradient was reported to disappear following resolution of the ischemic syndrome. Furthermore, it was reported that LVOT obstruction in the setting of acute myocardial infarction could predispose to cardiac rupture. We describe four cases with acute anterior myocardial infarction complicated with a dynamic LVOT obstruction documented by transthoracic Doppler echocardiogram. The detection of the dynamic LVOT obstruction allowed us to optimize the pharmacological treatment in each case. In spite of therapy, two of our patients worsened progressively to fatal cardiogenic shock and cardiac rupture. In conclusion, the development of a LVOT obstruction during acute anterior myocardial infarction has to be considered a serious and potentially fatal complication.

Left Ventricular Outflow Tract Obstruction Provoked by Catecholamine in Acute Myocardial Infarction: Mechanistic Insights From An Animal Experiment

“…This is consistent with the clinical observation that patients with anterior AMI may occasionally develop significant LVOT obstruc- tion, especially during catecholamine infusion [1][2][3][4][5]. The significant relationship between reduced mitral annular size and the provoked LVOT obstruction by dobutamine infusion in the presence of anterior AMI is also consistent with the previous observation that excessive mitral leaflets beyond coaptation is the critical factor to cause LVOT obstruction or SAM in patients with hypertrophic cardiomyopathy [7][8][9][10][11].…”

“…This study further demonstrated that reduced anteroposterior dimension of the mitral annulus with augmented basal posterior LV contraction is related to the provoked LVOT obstruction by dobutamine infusion in the presence of anterior AMI. Utility LVOT obstruction following catecholamine infusion in anteroseptal AMI causes serious hemodynamic deterioration [1][2][3][4][5]. This study has demonstrated a potential relation between the provoked LVOT obstruction and reduced antero-posterior mitral annular dimension with hyperdynamic basal posterior LV wall.…”

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IntroductionSerious hemodynamic deterioration by left ventricular outflow tract (LVOT) obstruction following catecholamine infusion in anteroseptal acute myocardial infarction (AMI) has been reported [1][2][3][4][5]. It has been reported that LVOT obstruction in hypertrophic obstructive cardiomyopathy (HOCM) is related to 1) excessive anterior mitral leaflets beyond coaptation due to anteriorly located papillary muscles and abnormally elongated leaflets [6][7][8][9][10][11][12], 2) excessive posterior mitral leaflets [13], 3) reduced chordal tension, and others.

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Dynamic Intraventricular Obstruction in Acute Myocardial Infarction With Administration of Cilostazol

“…However, there have been some reports of patients with transient intraventricular obstruction during AMI who experienced myocardial rupture and subsequently died as a result. 3,6 Dynamic intraventricular obstruction is initially diagnosed with the detection of a new ejection systolic murmur, as in this case. Mitral regurgitation and ventricular septal perforation are well-recognized complications of AMI with a new systolic murmur.…”

“…Recently, there have been some reports of dynamic intraventricular obstruction in the setting of AMI that resulted in a systolic murmur. [1][2][3][4][5][6][7] Moreover, dynamic intraventricular obstruction could be associated with a catastrophic medical outcome. We report a case of transient dynamic intraventricular obstruction in AMI following administration of cilostazol.…”