Use of Magnetic Field Mapping in the Evaluation of Patients With Hypertrophic Heart Disease (Thick Heart Muscle)

Patients with hypertrophic cardiomyopathy (HCM) have a gene mutation that results in excessive thickening of heart muscle. Due to this abnormality these patients often present with voltage changes on electrocardiograms (ECG) suggestive of abnormal electrical conduction. The use of magnetocardiography (MCG) in these patients has yet to be extensively studied. Magnetocardiography (MCG) is a safe, non-invasive, and FDA approved technology that can be used to detect weak magnetic fields generated by the heart. The goal of this pilot study is to determine common MCG findings in patients with HCM, while establishing the role that MCG has in the evaluation and treatment of these patients.

We will enroll a total of twenty patients identified to have hypertrophic cardiomyopathy by cardiologists at our facility. As patients' enroll in the study, data will be collected prospectively. We will continue to follow up on patients over the course of 1 year from the date of their initial enrollment. Once a patient has been identified as a candidate for this study, they will be instructed about the risks and benefits of undergoing participation. Informed consent to participate in the study will be obtained for each patient.

We will obtain basic demographic information on our patients including sex, age, race, weight, height, and other co-morbidities and cardiovascular risk factors including, but not limited to family history of syncope, sudden cardiac death, chest pain, or shortness of breath. Information in regards to symptoms experienced, onset of symptoms, previous and current diagnostic workup included blood work and cardiac scans, and current/past treatments will also be recorded. A list of medications will be recorded.

Prior to the MCG scan, the patient will be instructed to wear only non-metallic containing clothing. Patients's will then be requested to lie still on a table for a duration of 6 minutes, while undergoing a magnetocardiography scan. In addition to the MCG, the patient's blood pressure and a 12-lead electrocardiogram will be obtained. Most patients will also have a complete 2D echocardiogram which will require the patient to lie down on a table while an ultrasound probe is placed on the left side of the chest resulting in an image of the heart on a computer screen. In addition to the above, if clinically indicated patients may have blood draws taken at the discretion of their cardiologist. These blood draws may be used to obtain lipid levels, cardiac biomarkers, and natriuretic peptide assays (used to evaluate heart failure).

Once a patient has completed an initial assessment and scan, we will ask the patient to return for follow up visits at 3 months and 1 year for repeat MCG. A 2D ECHO will be obtained at 3 months if clinically indicated, and at 1 year. In addition, we are asking for follow up scans if the patient presents with any cardiac symptoms such as chest pain, shortness of breath, or fainting Follow up phone interview will occur at 6 months. We will ask information regarding symptoms, treatments, hospital admissions, cardiologist visits, and any subsequent diagnostic testing performed including ECGs, transthoracic echos, transesophageal echos, exercise/chemical stress testing, angiograms, and cardiac catheterizations.