What is Postinfarction Ventricular Septal Rupture?
Severe complications following a specific type of heart attack known as an acute ST-elevation myocardial infarction (STEMI) can include tearing or breaking of heart muscle tissue that has been damaged by the heart attack. The symptoms of these complications might change depending on where the rupture occurs; it could happen on the outer wall of either of the heart’s main pumping chambers (the ventricles), the wall separating the ventricles (the interventricular septum), or the muscles responsible for controlling the heart valves (the papillary muscles). A ventricular septal rupture (VSR) following a heart attack is particularly feared as it can lead to serious health complications and has a high fatality rate in patients with STEMI.
What Causes Postinfarction Ventricular Septal Rupture?
VSR, or ventricular septal rupture, tends to happen more often in older patients, women, people with high blood pressure and chronic kidney disease, and among those who haven’t smoked before. It often happens after a person has their first heart attack, particularly if treatment to restore blood flow to the heart was delayed or didn’t take place.
Usually, a special type of heart scan called an angiography will show that there’s no way for blood to get to the area of the heart that’s been damaged.
But interestingly, people who have conditions that can cause the heart to get less blood than normal over a long period – like diabetes, chronic chest pain (angina), or a previous heart attack – are less likely see their heart rupture. This is likely because their heart has been able to get used to less blood flow, reducing the chance that their heart muscle will die and rip apart.
The rupture usually develops between 1 to 14 days after a type of heart attack called ST-Elevation Myocardial Infarction (STEMI). However, it’s most likely to happen either within the first 24 hours or between 3 to 5 days after the heart attack.
Risk Factors and Frequency for Postinfarction Ventricular Septal Rupture
Post-myocardial infarction VSR, a heart complication, is found in 1% to 3% of patients with STEMI who didn’t receive reperfusion therapy, a treatment that restores blood flow to the heart. However, it only occurs in 0.2% to 0.34% of patients who receive fibrinolytic therapy, which is a method to dissolve blood clots. It’s found more frequently in patients who’ve had fibrinolytic therapy compared to those who’ve had a percutaneous coronary intervention, a non-surgical procedure used to treat blocked heart arteries. In cases where STEMI leads to cardiogenic shock, a serious condition that can cause organ failure due to insufficient blood flow, the incidence of VSR rises to 3.9%.
Signs and Symptoms of Postinfarction Ventricular Septal Rupture
People with a condition known as ventricular septal rupture, which can happen following a heart attack, might initially feel all right. However, they could suddenly experience a repeat of chest pain, fluid in the lungs, low blood pressure, and shock. Sometimes, these symptoms might be the very first indications of the condition.
If a person develops a new heart murmur, has worsening heart health, and experiences failure of both heart chambers (biventricular failure), these circumstances suggest they may have this condition. A heart murmur related to a post-heart attack ventricular septal rupture can usually be heard best towards the bottom of the left side of the breastbone. Additionally, half of the time there might also be a noticeable vibration caused by the irregular blood flow (thrill).
All individuals who experience a heart attack must go through an initial heart check-up and regular follow-ups after that. However, it’s important to remember that not all patients with a large ventricular septal rupture and severe heart failure or shock from inadequate blood flow will have a loud heart murmur—sometimes it’s quiet or even inaudible. It’s also worth noting that just because there is no heart murmur, it doesn’t mean the condition isn’t there.
Testing for Postinfarction Ventricular Septal Rupture
The electrocardiogram or ECG is key in diagnosing STEMI, a type of heart attack. When a ventricular septal rupture (VSR) happens after a heart attack, the ECG might also reveal different types of conduction abnormalities in about 40% of patients.
Transthoracic echocardiography (TTE), essentially an ultrasound of the heart, is the preferred test for diagnosing VSR. This imaging helps identify the size and location of the rupture, determining the degree of blood flow from the left to the right side of the heart (left-to-right shunt). The rupture is best viewed by angling the ultrasound beam differently based on the rupture’s location. It also assesses whether devices that seal the rupture can be used and evaluates the heart’s function, both vital for predicting outcomes and deciding treatments.
Right heart catheterization is another beneficial test. A small catheter fed through your veins into your heart reveals an increase in oxygen levels in the right ventricle and pulmonary artery – a key sign of VSR. This rise in oxygen levels can help distinguish VSR from a condition where one of the heart valves doesn’t function properly after a heart attack.
Left heart catheterization involving a small catheter inserted through your arteries into your heart can show VSR, particularly when viewed from certain angles.
Cardiac MRI and CT scans, which use magnets and radio waves or X-rays to create detailed images of the heart, can also be used. However, these can be more challenging to perform in patients who are not stable and do not play a significant role in patients with VSR.
Treatment Options for Postinfarction Ventricular Septal Rupture
When someone has a ventricular septal rupture (VSR) after a heart attack, doctors usually recommend continuous close monitoring. This helps doctors understand the pressure inside both heart ventricles (chambers of the heart that push blood out of the heart). That way, they can adjust the amount of fluids given to the patient and the usage of diuretics, which are medications that help the body get rid of excess salt and water. They can also measure the patient’s cardiac output, which is the amount of blood the heart pumps out, and mean arterial pressure to calculate the patient’s systemic vascular resistance. This helps them guide the therapy to relax and widen the blood vessels. If the patient’s blood pressure is above 90 mm Hg, medications like nitroglycerine or nitroprusside that help widen the blood vessels should be started as soon as possible. Sometimes, medications called inotropes may also be needed to increase the heart’s ability to pump blood. These measures are important to stabilize the patient before further tests and repair procedures are carried out. If medication doesn’t help achieve stability or if the patient doesn’t tolerate it, a treatment method called intra-aortic balloon counterpulsation (IABP), which is a procedure to help your heart pump more blood, should be considered.
The best treatment for a post-heart attack VSR is an urgent surgical closure. Some people believe that delaying the surgery can give time for the damaged tissue to heal, which may result in a lower rate of death from the surgery. However, these conclusions could be influenced by selection bias, where the results are skewed by the type of patients chosen for the study. Fatalities for patients with VSR who only receive medication are quite high: 24% at 72 hours and up to 75% at three weeks. The death rate from surgery is higher in patients who have specific types of heart attacks. Patients who had a heart attack at the bottom of the heart have a 70% surgical mortality rate compared to 30% for those who had a heart attack affecting the front of the heart. This discrepancy is due to the more challenging surgical technique and the need for additional valve repair in these patients, as they often have a condition called mitral regurgitation, where the blood flows backward from the heart.
While surgery is the most effective treatment for post-heart attack VSR, doctors are increasingly trying a less invasive method known as percutaneous closure, particularly in patients with a high risk for surgery. This is a procedure where the doctor inserts a small device through a vein and guides it to the heart to close the hole.
What else can Postinfarction Ventricular Septal Rupture be?
In patients experiencing a specific kind of heart attack known as STEMI, there might be sudden development of a loud heartbeat which could be due to either an issue with their mitral valve (acute mitral regurgitation) or a rupture in the wall separating the ventricles of their hearts (ventricular septum). Differentiating between these two conditions based solely on symptoms can be quite difficult.
However, there are two methods that can help in this situation:
- Using color flow Doppler echocardiography, a special form of ultrasound that shows the movement of blood through the heart.
- Performing a right heart catheterization, a procedure where a thin, flexible tube (a catheter) with a balloon on the end is inserted into the right side of the heart.
In the procedure of right heart catheterization, the blood’s oxygen saturation levels are measured in three places – the right ventricle, the pulmonary artery, and the right atrium. If there’s a significant increase in oxygen levels between the blood from the right atrium and that from the right ventricle or pulmonary artery, that indicates a ventricular septum rupture. If no such increase is observed, it may be acute mitral regurgitation. These patients might also show tall C-V waves in the readings of pulmonary capillary and arterial pressures.
