carbonic anhydrase inhibitors such as topiramate), surgery, and other procedures, or in people having a radiological study with administration of an iodinated contrast agent.Metformin is recommended to be temporarily discontinued before any procedure involving use of iodinated contrast agents, (such as a contrast-enhanced CT scan or angiogram) due to the increased risk of lactic acidosis resulting from impaired kidney function; metformin can be resumed after two days after contrast administration, if renal function is adequate and stable. Adverse effects
The most common adverse effect of metformin is gastrointestinal irritation, including diarrhea, cramps, nausea, vomiting, and increased flatulence; metformin is more commonly associated with gastrointestinal adverse effects than most other antidiabetic medications. The most serious potential adverse effect of metformin is lactic acidosis; this complication is rare, and the vast majority of these cases seem to be related to conditions such as impaired liver or kidney function, rather than to the metformin itself. Metformin is not approved for use in those with severe kidney disease, but may still be used at lower doses in those with kidney problems. Gastrointestinal
Gastrointestinal upset can cause severe discomfort; it is most common when metformin is first administered, or when the dose is increased. The discomfort can often be avoided by beginning at a low dose (1.0 to 1.7 g/day) and increasing the dose gradually, but even with low doses, 5% of people may be unable to tolerate metformin. Use of slow or extended-release preparations may improve tolerability.Long-term use of metformin has been associated with increased homocysteine levels and malabsorption of vitamin B12.
Diagnosis
Among the diagnostic procedures done to determine a cardiomyopathy are:
Physical exam
Family history
Blood test
ECG
Echocardiogram
Stress test
Genetic testing

Classification
Cardiomyopathies can be classified using different criteria:
Primary/intrinsic cardiomyopathiesCongenital
Hypertrophic cardiomyopathy (HCM)
Arrhythmogenic right ventricular cardiomyopathy (ARVC)
Left ventricular noncompaction
Ion Channelopathies like the Long QT syndrome and the very rare Short QT syndrome
Catecholaminergic polymorphic ventricular tachycardia
Mixed
Dilated cardiomyopathy (DCM)
Restrictive cardiomyopathy (RCM)
Brugada syndrome
Acquired
Stress cardiomyopathy
Myocarditis, inflammation of and injury to heart tissue due in part to its infiltration by lymphocytes and monocytes
Eosinophilic myocarditis, inflammation of and injury to heart tissue due in part to its infiltration by eosinophils
Ischemic cardiomyopathy (not formally included in the classification, due to ischemic cardiomyopathy being a direct result of another cardiac problem)
Secondary/extrinsic cardiomyopathiesMetabolic/storage
Fabrys disease
Hemochromatosis
Endomyocardial
Endomyocardial fibrosis
Hypereosinophilic syndrome
Endocrine
Diabetes mellitus
Hyperthyroidism
Acromegaly
Cardiofacial
Noonan syndrome
Neuromuscular
Muscular dystrophy
Friedreichs ataxia
Other
Obesity-associated cardiomyopathy

Treatment
Treatment may include suggestion of lifestyle changes to better manage the condition. Treatment depends on the type of cardiomyopathy and condition of disease, but may include medication (conservative treatment) or iatrogenic/implanted pacemakers for slow heart rates, defibrillators for those prone to fatal heart rhythms, ventricular assist devices (VADs) for severe heart failure, or catheter ablation for recurring dysrhythmias that cannot be eliminated by medication or mechanical cardioversion. The goal of treatment is often symptom relief, and some patients may eventually require a heart transplant. See also
Myopathy, a condition affecting skeletal muscles
Fibrosing cardiomyopathy, a disease in great apes
Basic Research in Cardiology

References
Further reading
Boudina, Sihem; Abel, Evan Dale (1 March 2010). "Diabetic cardiomyopathy, causes and effects". Reviews in Endocrine & Metabolic Disorders. 11 (1): 31–39. doi:10.1007/s11154-010-9131-7. ISSN 1389-9155. PMC 2914514. PMID 20180026. Marian, A. J.; Roberts, Robert (1 April 2001). "The Molecular Genetic Basis for Hypertrophic Cardiomyopathy".