Table 2.

Differential diagnosis for mechanical complications of acute myocardial infarction.

	Common Clinical Scenarioα	Features	Diagnosis	Management
Unrelated to Acute Myocardial Infarction
Dynamic LVOT obstruction	(1) As a manifestation of Hypertrophic cardiomyopathy	Hypotension exacerbated by vasopressor use, systolic murmur in the left ventricular outflow tract, frequently accompanied by systolic murmur of MR at apex.	Bedside echocardiography	- Judicious use of intravascular volume resuscitation and beta blockade
	(2) In the setting of inotrope/vasopressor use			- Discontinue IV vasodilators and inotropes
	(3) Stress Induced Cardiomyopathy			- Use of phenylephrine or vasopressin as a vasoconstrictor
Acute pulmonary embolism	Predisposing factor to PE or history of established DVT	Hypotension, tachycardia with clear lung field, with SOB and a significant alveolar-arterial gradient.	CT PE protocol +/− echocardiogram	- Activation of Pulmonary Embolism Response Team for consideration of medical, surgical or catheter-based intervention.
Acute valvular emergency	(1) Acute severe mitral regurgitation	Symptoms of left ventricular failure and auscultatory features of valve insufficiency, with orthopnea, tachycardia as primary features.	Bedside echo with low threshold to perform TEE.	- Medical stabilization/resuscitation
	(2) Acute severe Aortic regurgitation		Fluoroscopy or cine-CT for mechanical valves.	- Initiation of antibiotics if endocarditis related
	(3) Acute Prosthetic Valve failure	Prosthetic metallic valve may have absent click		- Possible surgery/structural intervention.
Cardiac Tamponade	Predisposing factor to tamponade	Hypotension, tachycardia, jugular venous distension, pulsus paradoxicus	Bedside echo, TEE if post-surgery and localized tamponade.	- Pericardiocentesis or surgical exploration as dictated by underlying etiology
Septic Shock	Predisposing factor to septic shock	Hypotension, tachycardia, elevated lactate Possible fever and leukocytosis	Echo/TEE to evaluate septic focus	- Correction of intravascular status
				- Appropriated anti-microbial therapy
				- Vasoactive drugs for hemodynamic support
				- surgical intervention or device removal if indicated.
				Acute Aortic Dissection	Type A dissection complicated by acute severe AI, acute coronary ischemia or pericardial tamponade.	Findings supportive of a dissection along with either murmur of aortic regurgitation, clinical findings of tamponade.	CT Aorta +/− Echo	- Absolute contraindication to antiplatelet medication / anticoagulants
- BP reduction and reducing shear stress with BB
- Emergent surgery
Related to AMI
LV predominant cardiogenic shock	Large LAD myocardial infarction or new infarction in setting of a prior ischemic cardiomyopathy.	Hypotension, tachycardia, pulmonary edema, oliguria, peripheral hypoperfusion.	Echo, coronary angiography with confirmatory right heart catheterization findings if performed.	- Revascularization as dictated by coronary anatomy
				- Possible temporary LV mechanical circulatory support.
RV predominant cardiogenic shock	Usually in the setting of RCA infarction with RV involvement.	EKG findings, hypotension, relatively clear lungs, elevated JVD	Echo, coronary angiography with confirmatory right heart catheterization findings if performed	- Revascularization
				- Possible institution of temporary RV mechanical support if indicated.
Dynamic LVOT obstruction	Dynamic LVOT obstruction in setting of a large LAD infarction.	LVOT murmur occasionally accompanied by systolic MR murmur	Echo	- Judicious use of intravascular volume resuscitation and beta blockade and
				- Discontinue IV vasodilators and inotropes
				- Use of phenylephrine or vasopressin as a vasoconstrictor
Occult blood loss	Occult blood loss	Hypotension, reflex tachycardia may be blunted by beta blockade, decrease in hematocrit	CT looking for occult bleed, commonly RP, GI is a common source; endoscopy/colonoscopy.	- Stabilization and transfusion as needed, treat the primary bleeding source.
Drug Related	In setting of overzealous beta blockade or ACEi, IV NTG in a preload sensitive or intravascularly depleted state.	Hypotension	High clinical suspicion	- Modify pharmacotherapy as indicated.

Abbreviations: AMI = Acute Myocardial Infarction; MR = Mitral Regurgitation; IV = intravenous; DVT = deep venous thrombosis; PE = pulmonary embolism; CT = computed tomography; TEE = transesophagreal echocardiography; AI = aortic insufficiency; LAD = left anterior descending artery; LV = left ventricle; RCA = right coronary artery; JVD = jugular venous distension; RV = right ventricle; LVOT = left ventricle outflow tract; Echo = Echocardiography; RP = Retroperitoneal; GI = gastrointestinal; ACEi = Angiotensin Converting Enzyme Inhibitor; NTG = Nitroglycerin.

^αPredisposing factors indicate clinical symptoms, signs, laboratory, and imaging characteristics suggestive of each clinical condition