Left ventricular hypertrophy is one of the most common clinical cardiac entity.It is recognised either by ECG or echocardiography.LVH has a unique place in cardiology as it can imply a grossly pathological state or a marker of healthy heart as in physiological hypertrophy in athletes.
Logic would suggest , in this era of stem cells and nano medicine , every muscle fibre in ventricle is worth in gold !. So when the nature provides an extra reserve of myocardium in the form of LVH one should welcome it , if otherwise not harmful.
Is LVH due to systemic hypertension benign ?
Not really, LVH has been shown to be an independent cardiac risk factor. (The famous Framingham study)Further LVH can result in diastolic dysfunction and the risk of cardiac failure increases.
But in spite of these observations, an astute clinician with considerable experience will appreciate , patients with LVH fare better during an acute coronary syndrome !
This has been a consistent clinical observation . (Shall we call it as class C . ACC /AHA evidence ? )
Is LVH an asset during ACS ?
- A hypertrophied heart takes ischemic injury very easy , it doesn’t really hurt much . Another possibility is that in LVH myocytes are relatively resistant to hypoxia .
- Patients with LVH rarely show significant wall motion defect following an STEMI.This is probably because the full thickness transmural necrosis is almost never possible even if extensive MI occurs.
- This is also reflected in ECG as these patients rarely develop q waves in following STEMI .
- Persistent ST elevation and failed thrombolysis is very uncommon in pateints with LVH.
- LVH provides a relative immunity against development of cardiogenic shock . It requires 40% of LV mass destruction to produce cardiogenic shock.This can rarely happen in LVH. In a long term analysis we have found none of the patient with LVH developed cardiogenic shock following STEMI.
- LVH patients are also protected against development of free wall rupture.
“Lack of evidence does not make a fact , a myth”
LVH , either pathological or physiological , has a hither to unreported beneficial effect .It acts as a myocardial reserve and help limit the impact of STEMI .