ACCSAP Cardiomyopathies Flashcards
What is excitation-contraction coupling?
Entry of calcium into the cell occurs first. Subsequently, there is release of calcium from the sarcoplasmic reticulum (calcium-induced calcium release). Calcium binds to troponin C, inducing conformational changes that displace tropomyosin from the actin-binding sites. There is cross bridge formation between myosin and actin with adenosine triphosphate hydrolysis. The power stroke consists of the movement of myosin heads along the actin filament. Adenosine triphosphate-binding is needed for release of myosin heads from the actin filament.
Class I recommendation for endomyocardial biopsy?
new-onset heart failure of 2 weeks to 3 months duration with a dilated LV and new ventricular arrhythmias, second- or third-degree heart block, or failure to respond to usual care within 1 to 2 weeks.
What is the best way to determine prognosis in HF patients?
Assessment of functional capacity using cardiopulmonary exercise testing. The accepted indication for heart transplantation is an oxygen consumption of <14 cc/kg/min (or 12 cc/kg/min in the presence of beta-blockers) measured during a cardiopulmonary exercise test.
What is the inheritance pattern of Fabry’s disease?
X-linked (recessive). So it will commonly skip female carriers and more likely to afflict male family members.
presentation with HF in the setting of reasonably preserved EF associated with chest pain, normal coronary arteries, LV hypertrophy, and renal dysfunction is most typical of Fabry’s disease.
Genetic abnormality - Name the phenotype:
- Plakoglobin
- Myosin Heavy chain
- Tafazzin
- Plakoglobin - ARVC
- Myosin Heavy chain - Dilated and hypertrophic CM
- Tafazzin - LV Noncompaction, dilated CM
Most common cause of death within 30 days after transplant?
primary graft failure, defined as dysfunction of the transplanted organ within the first 24 hours. More common with older donor organs and longer ischemic time.
Acute cellular rejection - first year post transplant
Most common cause death at 5 years is malignancy
Diagnostic criteria for familial CM?
clinical diagnosis and requires three generations to be affected. It is usually autosomal dominant. Genetic testing can be useful but is not currently necessary to establish the diagnosis of a familial cardiomyopathy.
Peripartum cardiomyopathy.
If EF has recovered >50%, what is risk of PPCM with another pregnancy?
If EF not recovered, what is risk of mortality with subsequent pregnancy?
Women who recovered their LVEF had a 21% risk of recurrence with subsequent pregnancy, but there were no maternal deaths. In the patients with persistent LV dysfunction, there was a 44% risk of recurrent heart failure and a 19% risk of maternal mortality with subsequent pregnancy.
What are class I recommendations for ICD in HCM? What are class IIa indications?
Class I = personal history of sudden cardiac death (SCD), ventricular fibrillation, or hemodynamically significant VT
Class IIa = first-degree relative with SCD, maximum wall thickness >30 mm, and one or more recent syncopal episodes.
What are class I recommendations for ICD in HCM? What are class IIa indications?
Class I = personal history of sudden cardiac death (SCD), ventricular fibrillation, or hemodynamically significant VT
Class IIa = first-degree relative with SCD, maximum wall thickness >30 mm, and one or more recent syncopal episodes.
In HCM patients with NSVT or abnormal blood pressure response to exercise, other risk factors must be present to warrant implantation of an ICD. These other risk factors include resting LV outflow tract obstruction >30 mm Hg, gadolinium enhancement representing myocardial fibrosis by cardiac magnetic resonance, and LV apical aneurysm.
What are some methods of remodeling after MI?
Persistent activation of the sympathetic nervous system, partly mediated through norepinephrine, as well as activation of the renin-angiotensin-aldosterone system result in increased endothelin-1 production, collagen turnover, reduced nitric oxide activity, and cellular apoptosis.
Based on the Food and Drug Administration-approved labeling for doxorubicin, when should therapy be discontinued?
an EF drop of ≥10% to an absolute level <50% should prompt discontinuation of chemotherapy and consideration for initiation of angiotensin-converting enzyme inhibitors or beta-blockers. After a cumulative dose of 500 mg/m2, repeat evaluation should be considered for every additional 50 mg/m2 of doxorubicin administered
Risk factors that increase anthracycline toxicity are?
1) total lifetime dose of anthracycline; 2) intravenous bolus administration; 3) higher single doses; 4) history of prior mediastinal irradiation; 5) use of other concomitant agents known to have cardiotoxic effects, such as cyclophosphamide, trastuzumab, and paclitaxel; 6) female sex; 7) underlying cardiovascular disease; 8) extremes of patient age (both very young and old age); and 9) increased length of time since anthracycline completion.
Indication to add ARB to a patient with HF?
Aldosterone-receptor antagonists are recommended in patients with NYHA class II-IV heart failure with an LVEF of 35% or less, unless contraindicated, to reduce morbidity and mortality.
Creatinine should be <2.5 mg/dl in men and <2.0 mg/dl in women, and potassium <5 mEq/L.
What is the 5-year mortality rate among individuals newly diagnosed with heart failure?
50% mortality at 5 years
