Shone’s Disease a rare congenital heart syndrome

Shone’ Syndrome

  • A rare congenital heart disease described by Shone in 1963
  • Manifests as decreased left ventricular output
  • There are two types of Shone’s syndrome: complete and incomplete Shone’s syndrome.
  • In the complete form of Shone’s syndrome, all four of the lesions will be present.

In the incomplete form, two or three lesions will be present (more common)

Supravalvular mitral membrane (SVMM): Typically the first abnormality to develop. An abnormal ridge of connective tissue on the atrial side of the mitral valve. Often the supravalvular ring may encroach on the orifice of the mitral valve leaflets and restricts their movements. While a supravalvular mitral ring may allow normal haemodynamic flow from the left atrium to the left ventricle, it often causes an obstruction of the mitral valve inflow(cite). Mitral supravalvular ring is associated with other defects in almost 90% of cases

Valvular Mitral Valve stenosis due to a parachute mitral valve: The mitral valve chordae insert into one papillary muscle. In parachute-like asymmetric mitral valve, most or all chordal attachments are to one papillary muscl. This abnormal attachment of the chordae tendonae results in stenosis of the mitral valve since the valves are held in close proximity.

Subaortic stenosis (membranous or muscular): is a fixed form of anatomic obstruction to outlet of blood across the left ventricular outflow tract. There are four basic anatomic variants which are as follows: (1) a thin discrete membrane consisting of endocardial fold and fibrous tissue, (2) a fibromuscular ridge consisting of a thickened membrane with a muscular base at the crest of the interventricular septum, (3) a diffuse, fibromuscular, tunnel-like narrowing of the LVOT, and (4) accessory or anomalous mitral valve tissue.

Aortic Coarctation: Coarctation of the aorta is a narrowing of the aorta most commonly found just distal to the origin of the left subclavian artery. Since the narrowing occurs distal to the L subclavian artery symptoms typically are manifested in the lower extremities such as cramps, cold feet and decreased ability to perform exercise. Aortic coarctation occurs in 20–59% of cases with mitral valve anomalies

Here is an illustration of the pathology:

Untitled

Associated Pathologies
Heart failure, pulmonary hypertension, pulmonary edema, right ventricular hypertrophy, Left ventricular hypoplasia, pneumonia and cor pulmonale.

Diagnostic Imaging:
Echocardiogram, Pulmonary Artery catherization, MRI, chest radiograph, heart auscultation, EKG

Clinical Exam/Findings:
Loud S2, cold feet, bilateral rales/crackles. Orthopnea, diastolic murmur, atrial fibrillation, low cardiac output,

Prognosis:
If detected early surgery can be performed to correct the defects and is typically done in stages, which reduce dysfunctions. The longer the patient goes untreated and the more elevated pulmonary artery pressure increases the more worse the outcome.

heartbaby

A happy patient post surgery 🙂

Differential Diagnosis:
Tetraology of Fallot, Cor triastrium sinister, patent ductus arteriousum, bicuspid aortic valve

Works Cited

  1. Iwata Y, Imai Y, Shin’oka T, Kurosawa H. Subaortic stenosis associated with systolic anterior motion. Heart Vessels. Nov 2008;23(6):436-9.
  2. Morris et al, CT and MR Imaging of the Mitral Valve: Radiologic-Pathologic Correlation, RadioGraphics, October 2010; 30, 1603-1620.
  3. Otto CM, Bonow RO. Valvular heart disease. In: Libby P, Bonow RO, Mann DL, Zipes DP, editors. , eds. Braunwald’s Heart Disease: A Textbook of Cardiovascular Medicine 8th ed.Philadelphia, PA: WB Saunders; 2007:1625-1712
  4. Bonow RO, Carabello BA, Chatterjee K, et al. 2008 Focused update incorporated into the ACC/AHA 2006 guidelines for the management of patients with valvular heart disease: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines Circulation 2008;118:e523-e661.
  5. Serra W*, Testa P and Ardissino P Mitral supravalvular ring: a case report, Cardiovascular Ultrasound 2005, 3:19
  6. Popescu BA, Jurcut R, Serban M, Parascan L, Ginghina C. Shone’s syndrome diagnosed with echocardiography and confirmed at pathology, Eur J Echocardiogr. 2008 Nov;9(6):865-7
  7. Board, A.D.A.M. Editorial. Coarctation of the Aorta. U.S. National Library of Medicine, 18 Jan. 0001. Web. 08 Mar. 2013.
  8. Brauner R A, Laks H, Drinkwater DC Jr, Scholl F, McCaffery S. Multiple left heart obstructions (Shone’s anomaly) with mitral valve involvement: long-term surgical outcome. Ann Thorac Surg 1997;64:721-9

Adverse Cardiometabolic responses to exercise: A review and opinion

On May 30th 2012 the New York times published an article (http://well.blogs.nytimes.com/2012/05/30/can-exercise-be-bad-for-you/) on a study by Bouchard et al (http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0037887) which had discovered significant cardiometabolic adverse reactions in patients following exercise interventions. This report combined the findings of 6 studies and had a total of 1,687 subjects of various levels of health, risk factors, gender and age. These findings were quite profound in that currently exercise particularly aerobic exercise is recommended for patients to prevent or reduce the risk of cardiovascular pathologies. There have been numerous studies that support these claims; all one would have to do is search “exercise and cardiac benefits” to PubMed or even google and a plethora of articles in respectable journals would appear. It must be noted that the overwhelming majority of the interventions evaluated were endurance exercise, only two of the studies evaluated had subjects perform resistance exercise and of those two only one of the studies’ data was used in this report.

The authors of this study are all well known and reputable and after reading the article myself I feel that their findings are solid. They effectively controlled for error in measurement by only classifying AR to be greater than 2  standard deviations from the average to even be considered ‘significant”. Their statistical analyses also controlled for bias due to duration, gender and other variables. Their population pool was enormous and quite variable and the dosage of exercise was considerably mixed which made these findings very generalizable.

With all this being said I would agree with the authors in that stating though these findings do suggest that their may be a “statistically significant” percentage of people who experienced a deleterious effect from exercise, about 10% on average, one must must also realize that close to 90% of people did have positive benefit. When you take a step back and re-review these findings you realize that these findings are not that surprising. Any intervention there is always a chance for negative effects. Look at all of the drug therapies that are currently implemented, almost all could cause an adverse effect in a given patient. We are all very similar but we are all different at the cellular level and molecular level. If we were to abandon every intervention because 10% of the population have a negative side-effect we wouldn’t have that many left. The beauty of the healthcare system is that we have such variability in the way we can intervene with patients and treat pathologies. When the standard doesn’t work you try something else. The same should be said for exercise as well.

As a future physical therapist I feel that this issue is something that we can get involved in. By that I mean what the authors suggested in their discussion which is that there is a 20-30% genetic link for some of these ARs. This finding suggests the need for blood work and pre-screening of patient before and exercise plan is ever administered especially to “at risk” patients. The most effective and efficient way to pre-screen someone for exercise is to administer a stress test which physical therapists are now doing more often with the progression of cardiac rehab. We have a chance to really get involve in this and I hope more research is done in the future in evaluating the ability of a stress test’s and concurrent blood work data at predicting ARs for patients. Too often exercise is prescribed capriciously with out considering that you may hurt your patient if you aren’t careful and treat the intervention as a medicine.

I would also like future research to look at the combination of resistance exercise and aerobic on metabolic risk factors. This study only had one group that did both and they had ARs but less in total, they also had one of the smaller sample sizes and were not American.

That’s enough from me take a look at the article and leave your comments below. Time to play cricket followed by watching the UFC fights.

Cheers guys

-Rich