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Archive for May 9th, 2010

Heart is one of the unique organs , that a physician can touch and feel before diagnosing a disease .The fact that ,  the heart is located superficially within the thoracic cavity makes tactile examination possible . The current generation cardiologists should realise cardiac palpation was a huge scientific specialty by itself centuries ago . Apical impulse demonstration  in class rooms  would go on for hours together in the days of Leannc and Dressler .

It is an irony , when we are able to see and feel many areas of the heart in the direct vision ( RV parasternal impulse, pulmonary arterial pulsation, contractility of LV ) we got addicted to imaging modalities now.

This article tries to extrapolate the  morphology of  apical impulse  with that of ehocardiographic LV function . A normal apical impulse is a very subtle impulse often absent in a third of population.Some times it is called tapping impulse .The  two common abnormalities  of apical  impulse are hyperdynamic and heaving .

Read the link for normal apical impulse

A hyperdynamic apical impulse

The  hyperdynamic apical impulse is diffuse (Occupying at least two rib spaces >  3Sqcms) and very active  with brisk motions visible to naked eye .This implies the leftventricle is dilated significantly and the wall is not much hypertrophied. This is eccentric LV enlargement . It also tells us the LV function is well-preserved as the term hyperdynamic infers very active LV .It is obvious , a dysfunctional LV can not be hyperactive. A hyperdynamic LV apex in a patients with AR or MR indicates they will do well after surgery for the simple reason their LV function is preserved. In the same logic a patient with hyperdynamic apex often complaints of palpitation as the apex hits the chestwall . Which is a good sign with reference to LV function .

Note :A patient with heaving apex rarely complaints of palpitation.

Hyperdynamism occur in systole or diastole ?

Logic would say apical impulse would be palpable only in  systole .But in a hyperdynamic LV diastolic phase is also palpable (A palpable S3 is common associate of hyperdynamic apex)

Heaving apical impulse

The term heaving apex by definition indicate there is a brief localized sustained LV apex lasting at least 50% of systole.

  •  Aortic stenosis with normal LV function
  • Any dysfunctional and dilated LV which increases the after load

The sustained lift may disappear with very severe LV dysfunction , apical impulse is barely perceptible in failing hearts . A sustained LV apex suggest reduced dp/dt of  LV contractility .

Relationship between apical impulse character and LVH ?

Hyperdynamic LV apex is rare to be associated with LVH .Except probably in HOCM where the LV systole is interrupted very early in the ejection phase.

Heaving apex can be a marker of LVH .But, the onset of LV dysfunction can confound this finding.

Can a hyperdynamic and heaving characters occur together in apical impulse?

We have been taught cardiology with a black and white learning concept but unfortunately science more often exists in shades of grey An apical impulse can indeed have characters of both . A diffuse apical impulse with a heaving nature is common in regurgitating lesions with the onset of LV dysfunction Such situation can occur in LV apical aneurysm

Final message

Looking for apical impulse in current cardiology practice  may be considered as  the most foolish job  a physician can indulge !

Ask the secretary to record the history ,  take an ECG, do an Echo  , send both deserving (and of course  many undeserving patients too !)  to cath lab at the earliest  . . . This is the  modern-day cardiology mantra !

This article , does not vouch  for the accuracy of   what  some may consider as  a  “medieval clinical sign” . But , it  confers the patient  a better rapport  strightaway   as  the physician  puts  his or her hand on the patients heart  . Some  call this  as a healing touch ! It work  wonders in many !

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Let ventricle is an elliptical or ovoid chamber .The pattern of LV enlargement can vary considerably in different pathologies. We know a dilated , globular heart is the typical feature of terminal congestive heart failure. But in the early stages of cadiac enlargement there are some distinct differences in the contour. (Aortic stenotic lesions retain the ellipitical shape till late in the course )

LV enlargement due to mitral regurgitation is somewhat different from aortic regurgitation. A globular configuration occurs more often in severe MR than AR. This is due to the fact, the long axis and short axis ratio of LV  is maintained till late in the course  of aortic valve disease . Cardiac long axis enlargement is more pronounced in aortic valve disease than in MR. The AR jet reaches LV  at a higher pressure gradient (Diastolic pressure of aorta) than mitral inflow velocity . (Often mimic physiological flow with an S3)

For a given degree of regurgitant volume AR will cause more cardiac enlargement than MR. In the same note , one should realise  the LA becomes huge in MR which receives high pressure regurgitant jet . Further ,mitral valve disease is more likely to result in early PAH and that results in right sided chamber enlargement giving the cardiac contour a more globular configuration

Is the cardiac contour different in rheumatic and degenerative(Myxamatous) mitral regurgitation ?

Yes , rheumatic MR results in less enlargement of the base of the heart as the fibrotic process restricts and restrains LV and prevents uncontrolled LV dilatation . In fact , giant LV are often  reported in mitral regurgitation due to mitral valve prolapse than rheumatic MR.

Why the configuration of LV important in the management of cadiac failure ?

The globular configuration of LV implies , the papillary muscles are attached in a disadvantaged angle and keep the free wall stress high. Specialized procedures are required to restore the LV shape especially in secondary to mitral annular dilatation. Isolated aortic valve disease rarely require LV remodeling surgeries , even if AVR is done late stages.

What is the maximum dimension of LV reported in cardiac failure ?

The upper limit of normal for LV diastolic dimension is 5.6cms. In MR it often reaches 6-7 cms . The maximum of 10cm has been reported with AR. An LV beyond this level looses it’s elasticity and likely to be incompatible with survival unless LV reduction surgeries like Batista are performed.

Is secondary valvular cardiomyopathy an accepted entity ?

 The  term cardiomyopathy when originally defined decades ago ,  required exclusion of all known cases of cardiac enlargement. But now we have a more liberal working concept , if the LV enlarges disproportionate to the loading conditions of the valvular lesions  , secondary cardiomyopathy is said to be present. If cadiomyopathy sets in,  the cardiac shape invariably takes in a globular configuration irrespective of the valvular lesions. So, the simple parameter of shape of LV in X ray chest can give us a clue regarding the outcome in valvular heart disease.

Further reading

Also read sphericity index by echocardiography A spherical LV can be easily quantified by echocardiography

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