Patient selection for percutaneous mitral valvuloplasty in mitral stenosis

Posted: Wednesday, May 11, 2011 | Posted by Debajyoti Datta | Labels: 6 comments

Mitral stenosis is a valvular heart disease in which the mitral valve, located between the left atrium and left ventricle of the heart, becomes narrowed resulting in obstruction of the blood flow between the left atrium and the left ventricle. The size of a normal mitral valve orifice is 4 - 6 cm2. Significant obstruction is present when the mitral valve area becomes less than 2 cm2.  Depending on the mitral valve area, mitral stenosis can be classified as mild (2 - 1.5 cm2), moderate (1.5 – 1 cm2) and severe (< 1cm2).

Heart mitral stenosis lpla view
Mitral stenosis
Mitral stenosis can occur due to the following causes –
  • Rheumatic fever
  • Congenital mitral valve stenosis
  • Severe mitral annular calcification
  • Systemic Lupus Erythematosus
  • Rheumatoid arthritis
  • Cor triatriatum
  • Infective endocarditis with large vegetation
  • Left atrial myxoma
Therapy for mitral stenosis has undergone a reorientation following the introduction of percutaneous mitral valvuloplasty. Percutaneous mitral valvuloplasty is indicated in symptomatic patients of mitral stenosis with the following characteristics –
  • Moderate or severe mitral stenosis
  • Valve morphology that favors percutaneous intervention
  • No thrombus in the left atrium or moderate or severe mitral regurgitation.
Percutaneous intervention for mitral stenosis is associated with some risks and hence is not indicated for asymptomatic patients except –
  • Patients with severe mitral stenosis who require other major noncardiac surgery
  • Young women who wish to become pregnant
  • Patients at high risk of thromboembolism
The immediate outcome of percutaeneous mitral valvuloplasty is predicted by an echocardiographic scoring system called the Wilkins scoring system.

Grade
Mobility
Subvalvar thickening
Thickening
Calcification
1
Highly mobile valve with only leaflet tips restricted
Minimal thickening just below the mitral leaflets
Leaflets near normal in thickness (4-5 mm)
A single area of increased echo brightness
2
Leaflet mid and base portions have normal mobility
Thickening of chordal structures extending up to one third of chordal length
Mid-leaflets normal, considerable thickening of margins (5-8 mm)
Scattered areas of brightness confined to leaflet margins
3
Valve continues to move forward in diastole, mainly from the base
Thickening extending to the distal third of the chords
Thickening extending to the entire leaflet (5-8 mm)
Brightness extending into the mid-portion of the leaflets
4
Brightness extending into the leaflets in diastole
Extensive thickening and shortening of all chordal structures extending down to the papillary muscles
Considerable thickening of all leaflet tissue (>8-10 m)
Extensive brightness throughout much of the leaflet tissue

A score of 8 or less is predictive of a good result with percutaneous mitral valvuloplasty.

ResearchBlogging.org
Guérios EE, Bueno R, Nercolini D, Tarastchuk J, Andrade P, Pacheco A, Faidiga A, Negrao S, & Barbosa A (2005). Mitral stenosis and percutaneous mitral valvuloplasty (part 1). The Journal of invasive cardiology, 17 (7), 382-6 PMID: 16003027
ResearchBlogging.org
Wilkins GT, Weyman AE, Abascal VM, Block PC, & Palacios IF (1988). Percutaneous balloon dilatation of the mitral valve: an analysis of echocardiographic variables related to outcome and the mechanism of dilatation. British heart journal, 60 (4), 299-308 PMID: 3190958

Initial assessment and management of Acute Heart Failure Syndromes

Posted: Saturday, May 7, 2011 | Posted by Debajyoti Datta | Labels: , 3 comments

I am back after a prolonged hiatus and will take a look at the early management of acute heart failure in this post. In a recent commentary published in JAMA, Mihai Gheorghiade and Eugene Braunwald, the doyen of cardiology have proposed a model for the assessment and management of patients presenting with acute heart failure. They consider patients in phase 1 of acute heart failure who require urgent treatment and stabilization.

The patients have been classified in a 6 axis model under the categories of –
  1. Clinical severity
  2. Blood pressure
  3. Heart rate and rhythm.
  4. Precipitants
  5. Comorbidities
  6. De novo or chronic heart failure
Modified from Gheorghiade M, & Braunwald E (2011). A proposed model for initial assessment and management of acute heart failure syndromes. JAMA : the journal of the American Medical Association, 305 (16), 1702-3 PMID: 21521852
I have summarized the model in the form of an algorithm. The grading of congestion is suggested to be done according to a scale available here.

However, there are few questions that remain unanswered.
  • The authors caution against the use of inotropes like dobutamine in patients with hypotension but what alternative therapy should be tried is not indicated.
  • The authors remark that in patients with concomitant renal abnormality, the interaction between heart failure and renal function is complex and the response to therapy may depend on this interaction but do not comment on the management of these subgroup of patients.
ResearchBlogging.org
Gheorghiade M, & Braunwald E (2011). A proposed model for initial assessment and management of acute heart failure syndromes. JAMA : the journal of the American Medical Association, 305 (16), 1702-3 PMID: 21521852