In 1847, Latham first introduced the diagnosis of ventricular septal rupture (VSR). The interventricular septum divides the ventricular chamber into right and left ventricles.
The interventricular septum consists of 2 parts;
A rare, but lethal complication of acute myocardial infarction is a ventricular septal rupture. The condition is rare because of an aggressive approach towards early reperfusion therapy, however, mortality is still high. Any part of the interventricular septum can develop a rupture. The size of the rupture determines the prognosis of the patient. The prognosis is good if the rupture is small and the patient is hemodynamically stable.
The most common cause of ventricular septal rupture is full-thickness (transmural) myocardial infarction in one of the following coronary arteries:
Partial thickness infarct such as Non-ST elevation myocardial infarction or unstable angina can also increase the risk of ventricular septal rupture
Before the invention of thrombolytic and percutaneous intervention, the incidence of ventricular septal rupture was approximately 2%. However, in the current period of thrombolytic and percutaneous intervention, especially with the aim of reducing door to intervention time, the incidence of ventricular rupture has been reduced to 0.31%. According to the Global Registry for Acute Coronary Events (GRACE) study, the rate of ventricular septal rupture in an acute myocardial infarction treated with percutaneous intervention is less (0.7%) than the myocardial infarction in patients treated with thrombolytic therapy(1.1%).  This study proved that the rate of ventricular septal rupture is less in patients who received an early thrombolytic or percutaneous intervention. The incidence also depends upon the type of myocardial infarction and is higher in patients with ST-segment elevation associated myocardial infarction (0.9%). Its occurrence in non-ST-segment elevation myocardial infarction and unstable angina is 0.17% and 0.25%, respectively. There is no difference in the rate of ventricular septal rupture based on the location of infarction whether it is anterior infarct or inferolateral infarct.
The most common pathological finding of an infarcted septum is coagulation necrosis, which is defined as dry denaturation of proteins due to lack of oxygen as a result of a loss in blood supply. It progresses to thinning and weakening of the septum. This process usually takes three to five days after acute myocardial infarction. The ventricular septal rupture can occur within 24 hours of myocardial infarction due to dissection of an intramural hematoma or hemorrhage into the diseased myocardium.
The primary mechanism behind ventricular septum rupture is physical shear stressors especially at the conjunction of infarct area and normal healthy myocardium. Due to this mechanism, ventricular aneurysm, free wall rupture, or papillary muscle rupture associated with ventricular septum rupture.
Cardiac free wall rupture and ventricular septum rupture after myocardial infarction are similar regarding pathological characteristics. There is a pathological classification regarding free wall rupture which we can use for ventricular septum rupture proposed by Becker. There are three types are as follows:
After the establishment of the new connection between right and left ventricle due to ventricular septum rupture, oxygenated blood shunts from the high-pressure left ventricle to the low-pressure right ventricle.
The patient may present with flash pulmonary edema after 1 to 3 days of a stable MI. Severe cases present as the cardiogenic shock. The risk factors for ventricular septal rupture include female gender, increased age, first episode of myocardial infarction, ST-segment elevation myocardial infarction, high GRACE risk score, and chronic kidney disease.. A patient having an acute myocardial infarction may present with hypotension or hemodynamically instability, and this should prompt evaluation for ventricular septal rupture. Characteristic signs the septal rupture include the development of a harsh systolic murmur with a palpable thrill over the precordium. Due to increased right heart flow sometimes there is a loud pulmonic component of the second heart sound, tricuspid regurgitation, or third heart sound.
Two-dimensional echocardiography with Doppler is used to diagnose ventricular septal rupture which shows a flow of blood across ventricular septum. Echocardiogram also demonstrates right ventricular dilatation and pulmonary hypertension due to increased right-sided blood flow. The color Doppler echocardiography is also useful in the evaluation of the anatomical size of a rupture.
Transoesophageal echocardiography is indicated in the patients in whom it is difficult to get an adequate view of the myocardium, for example in patients who are on a mechanical ventilator or have a large body habitus.
An interprofessional team, including an interventional cardiologist and cardiothoracic surgeon, is required to treat the ventricular septal rupture. The ultimate treatment of ventricular septal rupture is a surgical repair. Before surgical repair, it is necessary to restore the circulation in the diseased artery to decrease the hypoxic burden in the infarcted area especially in the cases of right ventricular involvement.
There are two surgical techniques for the repair of ventricular septal rupture are as follows:
The repair of a posterior ventricular septal rupture is more challenging than anterior rupture due to the proximity of papillary muscles.
If the ventricular septal rupture develops within 24 hours of an MI, surgical intervention is more difficult as it is difficult to differentiate between healthy and newly infarcted tissue; also, the muscle is weak and not able to hold the sutures.
Due to the reason mentioned above, the mortality of surgical intervention within 24 hours of acute myocardial infarction is over sixty percent. In contrast, untreated ventricular septal rupture has a death of 40% to 80%. Late surgical intervention has a good prognosis. Surgical intervention within seven days of this complication has the mortality of 54.1%. On the other hand, surgery after seven days has a death of 18.4%.
Patients presenting with cardiogenic shock need an intra-aortic balloon counterpulsation to reduce afterload and increase cardiac output.
Percutaneous intervention can repair anterior defects ventricular septal defects less than 1.5 cm in diameter, but this technique is still in an evolutionary phase.
The monitoring is essential in these patients. The surgical mortality is also high and requires close monitoring. The surgery should be done after the interactive discussion of the heart team amongst themselves and with the family. The prognosis is favorable if the rupture size is small and the patient is hemodynamically stable.
The patient will require long term cardiovascular rehabilitation and should be enrolled in a supervised exercise program.
An interprofessional approach to ventricular septal rupture is recommended involving physicians, nurses, and pharmacists working as a team to quickly evaluate and treat the patient.
Ventricular septal rupture is a life-threatening complication of an acute MI. Because of the very high mortality, a multidisciplinary approach is necessary. As soon as the diagnosis is confirmed we should notify the cardiac surgeon. Intensive care unit (ICU) monitoring is vital, and surgery should be undertaken emergently, depending on the hemodynamic status. Most patients require an intra-aortic balloon pump to assist with hemodynamics. Even after surgery, patients develop a whole host of complications including multiorgan failure and persistence of a shunt. When possible, the physician should manage residual shunts with a percutaneous closure device. Despite optimal treatment, the condition carries a mortality of more than 20%. (Level V)
|||Wenink AC, Embryology of the ventricular septum. Separate origin of its components. Virchows Archiv. A, Pathological anatomy and histology. 1981 [PubMed PMID: 7281475]|
|||Drazen JM, Expression of Concern: Beltrami AP et al. Evidence That Human Cardiac Myocytes Divide after Myocardial Infarction. N Engl J Med 2001;344:1750-7 and Quaini F et al. Chimerism of the Transplanted Heart. N Engl J Med 2002;346:5-15. The New England journal of medicine. 2018 Nov 8 [PubMed PMID: 30332558]|
|||Moreyra AE,Huang MS,Wilson AC,Deng Y,Cosgrove NM,Kostis JB, Trends in incidence and mortality rates of ventricular septal rupture during acute myocardial infarction. The American journal of cardiology. 2010 Oct 15 [PubMed PMID: 20920645]|
|||López-Sendón J,Gurfinkel EP,Lopez de Sa E,Agnelli G,Gore JM,Steg PG,Eagle KA,Cantador JR,Fitzgerald G,Granger CB, Factors related to heart rupture in acute coronary syndromes in the Global Registry of Acute Coronary Events. European heart journal. 2010 Jun [PubMed PMID: 20231153]|
|||Becker AE,van Mantgem JP, Cardiac tamponade. A study of 50 hearts. European journal of cardiology. 1975 Dec [PubMed PMID: 1193118]|
|||Huang SM,Huang SC,Wang CH,Wu IH,Chi NH,Yu HY,Hsu RB,Chang CI,Wang SS,Chen YS, Risk factors and outcome analysis after surgical management of ventricular septal rupture complicating acute myocardial infarction: a retrospective analysis. Journal of cardiothoracic surgery. 2015 May 4 [PubMed PMID: 25935413]|
|||Boettler P,Claus P,Herbots L,McLaughlin M,D'hooge J,Bijnens B,Ho SY,Kececioglu D,Sutherland GR, New aspects of the ventricular septum and its function: an echocardiographic study. Heart (British Cardiac Society). 2005 Oct [PubMed PMID: 15761045]|
|||Misawa Y, Off-pump sutureless repair for ischemic left ventricular free wall rupture: a systematic review. Journal of cardiothoracic surgery. 2017 May 19 [PubMed PMID: 28526037]|
|||Papalexopoulou N,Young CP,Attia RQ, What is the best timing of surgery in patients with post-infarct ventricular septal rupture? Interactive cardiovascular and thoracic surgery. 2013 Feb [PubMed PMID: 23143273]|
|||Attia R,Blauth C, Which patients might be suitable for a septal occluder device closure of postinfarction ventricular septal rupture rather than immediate surgery? Interactive cardiovascular and thoracic surgery. 2010 Nov [PubMed PMID: 20621996]|
|||Glancy DL,Khuri BN,Mustapha JA,Menon PV,Hanna EB, Myocardial infarction with ventricular septal rupture and cardiogenic shock. Proceedings (Baylor University. Medical Center). 2015 Oct [PubMed PMID: 26424959]|
|||Malhotra A,Patel K,Sharma P,Wadhawa V,Madan T,Khandeparkar J,Shah K,Patel S, Techniques, Timing & Prognosis of Post Infarct Ventricular Septal Repair: a Re-look at Old Dogmas. Brazilian journal of cardiovascular surgery. 2017 May-Jun [PubMed PMID: 28832791]|
|||Premchand RK,Garipalli R,Padmanabhan TN,Manik G, Percutaneous closure of post-myocardial infarction ventricular septal rupture - A single centre experience. Indian heart journal. 2017 Apr [PubMed PMID: 28400035]|