We know, electrical deaths constitute the bulk of sudden cardiac deaths in MI. Mechanical deaths due to pump failure, muscle rupture , valve leak , also cause significant deaths .(Surprisingly many of the mechanical deaths may also fulfill the sudden death criteria !)
Free wall rupture is invariably a fatal event. Papillary muscle trunk rupture leads to severe LVF and unless intervened sure to result in fatality.
The ones who tear their interventricular septum are some what blessed ! Here , the rupture does not result in instant death as there is no loss of blood , instead , there is an volume over load of right ventricle followed by the left ventricle after a few beats. Hypotension is the rule. Even though this is a major complication there is something about VSR which makes it unique.
Sudden giving way of IVS has a decompressing effect on the ailing left ventricle.This many times bring a temporary relief to LV and if the patient survives the first few hour he is likely to stabilise further . In fact , sudden deaths within 24hours after the onset of VSR is an exception.This defect always gives the cardiologists and surgeon some time to plan the management. We need to use this time judiciously.
The natural history is delicate . Five themes are possible
- Very unstable – Instant death( Fortunately a rare theme )
- Unstable – Deteriorating further
- Unstable to Stable * fit for discharge even without surgery
- Stable from the onset and continue to be stable* .
- Stable to Unstable (Probably the most common theme )
* Pleasant themes occasionally witnessed !)
Here is 55 year old women came with extensive anterior MI with lower septal rupture.(She belonged to type 3 of the above scheme)
The main determinant of survival is the underlying LV dysfunction and associated co morbidity(Renal function ) and complications .
Infero -posterior ruptures tend to be complex and may have multiple irregular tracks that makes it difficult to repair.
Echo cardiogram is the mainstay .Serial echos should be done to assess the mechanical function and the progress of VSR.Hemodynamic monitoring may be done without injuring the patient .
- Often supportive , but effective . Dobutamine infusion can maintain a life for few days.
- Paradoxically , LV dysfunction and elevated LVEDP restricts volume overloading of VSD.
- Associated MR, Arrhythmias need to be taken care of .
- Very Vital.
- Experience counts.(Individual as well as Institutional )
Timing of surgery
Continues to be a controversy . Surgeons love to operate in a stable patient. But they need to realise , surgery is often needed to stabilise many patients. . The issue of tissue friability is blown out of proportion in the literature .When a life is is at danger we can not worry about friable tissues !
The rule of thumb could be
- Operate as early as possible in unstable patient.
- Post pone surgery in stable patient as late as possible ( Late here means . . .elective non emergent surgery )
- Simple VSR closure without knowing coronary anatomy
- Simple VSR closure after knowing coronary anatomy
- VSR closure with CABG ( total revascularization)
- VSR closure with partial revascularization
In our experience each of the above , has a role in a given patient depending upon the logistic , financial , social and even the available expertise. (A good surgeon in bad Institution !)
Is coronary angiogram mandatory before attempting to close VSR ?
Logically yes. If it is not available just do not bother . But, many times , when issue is saving lives , we can not afford to be too scientific , many lives have been saved by not following such strict protocols .A simple emergency thoracotomy and closure of rupture site (Without even touching the LAD ) can be a distinct and viable option in a selected few .
Role of cardiologists
Contrary to the popular belief the role of cardiologists is minimal , except to prepare the patient and hand over to the surgeon.
Interventional approach to close a VSR is currently be termed as an adventurous option ! The VSRs can assume unpredictable shapes and the tears can be multiple in different planes. The devices , catheters and other hard ware are not specifically made to tackle these issues .An acquired VSR should never be compared with congenital VSD.