Suspicion of papillary muscle rupture should be considered in patients following the first week after myocardial infarction with sudden acute heart failure symptoms. A high level of suspicion should be contemplated in those with their first myocardial infarction that involves the inferior wall. Rapid, severe regurgitation from papillary muscle failure causes atrial dilatation secondary to an abrupt increase in atrial pressure. This coupled with a hyperactive precordium, and insufficient turbulence of blood through the regurgitant valve makes diagnosis clinically difficult at times because, often, there is not a stethoscopically audible regurgitant murmur. This is due to the equalization of pressures between the atria and ventricle. Patients who do have murmurs can have mid, late, or holosystolic murmurs.  Symptoms and physical findings are determined by the valve affected. The most papillary muscle chordae tendineae complex affected is the posterior-medial papillary muscle of the mitral valve involved, and thus acute left-sided heart failure symptoms are found which include rapidly progressive pulmonary edema and hypoxia. Cardiogenic shock with hypotension is also commonly observed. Chest pain has also been cited as a symptom in some patients. Given the swift onset of cardiogenic shock and catastrophic complications, prompt identification is important given the rise in mortality rates without emergency surgical intervention.

Identification of papillary muscle rupture and acute valvular insufficiency may be demonstrated by transthoracic (TTE) or transesophageal echocardiography (TEE). Transthoracic echocardiography may demonstrate a flail mitral valve leaflet with prolapse during systole into the atrium, visualization of a ruptured papillary muscle head with erratic movements in the ventricle or a mobile mass attached to the chordae tendinea. The sensitivity of TTE to visualize the structural abnormalities has been reported between 65-85%.  It is recommended to utilized transesophageal echocardiography with unequivocal TTE results, as TEE sensitivity has been reported as high as 92-100%. 

Many of these patients are too hemodynamically unstable to undergo invasive procedures, and thus TTE is typically the initial diagnostic method used. Doppler echocardiography and color flow imaging is also a helpful aid in identifying the severity of the regurgitant jet across the valve. Use of echocardiography is superior to cardiac catheterization as the muscle rupture can be diagnosed with minimal risk to the patient. In addition to acute valvular surgery,  coronary revascularization is strongly suggested, and those patients receiving such have demonstrated improved mortality rates.

The cornerstone of treatment for papillary muscle rupture includes emergency surgical treatment. Initial medical therapy can be instituted with diuretics, afterload reduction and oxygen therapy (bilevel positive airway pressure or mechanical ventilation may be necessary). Intra-aortic balloon counter-pulsation may be necessary for severely unstable patients. Previous intraoperative mortality associated with mitral valve repair in these patients was estimated to be 20% to 25%. More recently, a study from 2008 identified a decrease in operative mortality from mitral surgery (previous overall mortality of 18.5%) to be decreased to 8.7% when associated with coronary artery bypass grafting. However, the small sizes in these studies analyzing the surgical effectiveness of treating papillary muscle rupture leave this a controversial topic.

Another treatment controversy is whether mitral valve repair is more beneficial than valve replacement. At the time of this writing, repair over replacement is currently preferred unless necrotic papillary muscle tissue is present.

Concomitant coronary artery bypass has been shown to improve outcomes and should be done.

Suboptimal outcomes following valve repair have been linked to prolonged cross-clamp times, suturing into friable necrotic tissue and tissue remodeling after infarction. Partial papillary muscle rupture may be delayed by surgeons up to 6 to 8 weeks post-infarction to allow for necrotic tissue to resolve. This depends on the stability of the patient and may need to be surgically corrected sooner.

Other complications that may present with similar presentations include cardiogenic shock due to severe left and right ventricular dysfunction, ventricular septal rupture, and free-wall myocardial rupture. These are all post-myocardial infarction complications. Severe left ventricular dysfunction presented with pulmonary edema and decreased cardiac output leading to organ hypoperfusion. Severe right ventricular dysfunction presents with elevated jugular venous pressure, peripheral edema, hypotension, and clear lung fields. Right ventricular failure can also result in the underfilling of the left heart chambers that results in a low cardiac output state. Ventricular septal rupture has a 5% mortality rate and can be seen with anterior infarction, unlike papillary muscle rupture which is rarely seen in anterior cardiac ischemia.

Septal rupture occurs where necrotic tissue is located and creates a left-to-right shunt and new pansystolic murmur. Rapid pulmonary edema is typically not seen. Free-wall myocardial rupture is similar to septal rupture and papillary muscle rupture, in that small infarctions and single-vessel disease are often the etiologies. Left ventricular wall rupture is the most common site and occurs within five days in 50% of patients and within 2 weeks in 90% of patients. Survival depends on whether the rupture is complete or subacute with a high fatality rate (essentially 100%) in complete ruptures as this leads to abrupt onset cardiac tamponade.

One study evaluating 22 patients reported a perioperative mortality rate of 27% and overall survival of 47% at 7 years. Another study of 55 patients demonstrated an overall operative mortality rate of 24% with a higher mortality rate in patients who did not undergo coronary revascularization (39% versus 9%). Finally, in the third study of 54 patients, a 10-year survival rate was reported as 35%, and 10-year congestive heart failure-free rate was 23%.

• Cardiogenic shock
• Death

Immediate cardiology and cardiothoracic surgery consults are indicated in cases of suspected papillary muscle or chordae tendineae rupture.

Acute papillary muscle or chordae rupture and secondary acute valvular regurgitation should be considered in any patient presenting with acute pulmonary edema or shock, especially in the days following acute myocardial infarctions. These patients are highly unstable, and urgent cardiology and cardiovascular surgery consults are indicated. Mortality can be substantially reduced with rapid identification and referral for valvular repair or replacement and revascularization. The best initial study for identification in an unstable patient is transthoracic echocardiography, while transesophageal echocardiography is reserved for those with equivocal TTE studies.

Patients with a myocardial infarction are ideally managed by an interprofessional team that includes cardiology nurses. When papillary muscle is diagnosed, the patient must be prepared for immediate surgery. The only difficulty is the decision to perform a cardiac catheterization in an unstable patient. Some surgeons take the patient to the operating room without a cardiac catheterization assuming that the RCA/PDA is already involved. Because of the extremely high mortality following papillary muscle rupture, the focus today is on the prevention of coronary artery disease. The cardiology nurse, pharmacist and primary clinicians should educate the patients on the following:

• Participate in regular exercise
• Eat a healthy diet
• Remain in compliance with medications
• Abstain from alcohol
• Discontinue smoking
• Take statins as prescribed
• Maintain a healthy body weight
• Monitor and maintain normal blood pressure and blood glucose

Patients with risks for coronary artery disease must be closely followed and referred to a cardiologist for definitive care. Close communication between the team members is vital if one wants to improve outcomes. The outcomes for these patients are guarded. Without surgery, the disorder is fatal; even with surgery, recovery is slow.