Factors Contributing to Increased Left Ventricle Size in Patients With Abnormally Enlarged Hearts

NCT00001878 | Completed

• 2 other identifiers: 99005899-H-0058
• Study Type: observational
• Target: 175
• Locations: 1 country
• Sites: 1

Brief Summary

The human heart is divided into four chambers. One of the four chambers, the left ventricle, is the chamber mainly responsible for pumping blood out of the heart into the circulation. There is an inherited condition affecting the heart, passed on through genetics, hypertrophic cardiomyopathy (HCM). HCM causes the left ventricle to become abnormally enlarged (left ventricular hypertrophy LVH). Some patients with the abnormal genes that may cause HCM do not have the characteristic LVH. Approximately 20 - 40% of patients with the genetic abnormality (missense mutation of genes encoding for sarcomeric protein) actually have an enlarged left ventricle. Because of this, researchers believe there may be other factors, along with the genetic abnormality that contribute to the development of HCM. Researchers are interested in learning more about several factors they suspect may play a role in the development of HCM. Specifically, researchers plan to study levels of a hormone and the protein it attaches to, which may contribute to the development of an abnormally enlarged heart. Insulin-like growth factor (IGF-1) and insulin-like growth factor binding protein (IGFBP) work together with growth hormone (GH) in the development and maturation of many organ systems. Previous studies have suggested that these hormones affect the development and function of the heart. Patients participating in this study will undergo a variety of tests including collection of blood samples, echocardiogram of the heart, treadmill exercise test, and continuous electrical monitoring of heart activity (Holter monitor).

Conditions

Hypertrophic Cardiomyopathy; Left Ventricular Hypertrophy

Keywords

Growth Hormone; Cardiac Hypertrophy; Hypertrophic Cardiomyopathy; Sarcomeric Gene Mutations

Eligibility Criteria

• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)

You may qualify if:

• HCM subjects 5 years or older, with distinct sarcomeric gene mutations and LV wall thickness greater than 15 mm in subjects older than 18 years, and greater than 2 SDs in subjects 18 years of age or younger, as assessed by MRI.
• Age- and gender-matched blood relatives with sarcomeric gene mutations but without LVH.
• Age- and gender-matched blood relatives without sarcomeric gene mutations.

You may not qualify if:

• History of hypertension (basal systolic and diastolic pressures above 170 mm Hg and 95 mm Hg, respectively) or another systemic or cardiac disease that may cause cardiac hypertrophy.
• History of recent acute illness or other chronic illness that might affect plasma levels of IGF-I and IGFBP3.
• History of thyrotoxicosis, diabetes mellitus or abnormally elevated fasting blood sugar.
• Any conditions which would exclude patients from undergoing MRI scan.

Sponsors & Collaborators

• National Heart, Lung, and Blood Institute (NHLBI): lead

Study Sites (1)

National Heart, Lung and Blood Institute (NHLBI)

Bethesda, Maryland, 20892, United States

Location

Related Publications (3)

• Jarcho JA, McKenna W, Pare JA, Solomon SD, Holcombe RF, Dickie S, Levi T, Donis-Keller H, Seidman JG, Seidman CE. Mapping a gene for familial hypertrophic cardiomyopathy to chromosome 14q1. N Engl J Med. 1989 Nov 16;321(20):1372-8. doi: 10.1056/NEJM198911163212005.

  PMID: 2811944 BACKGROUND

• Rayment I, Holden HM, Sellers JR, Fananapazir L, Epstein ND. Structural interpretation of the mutations in the beta-cardiac myosin that have been implicated in familial hypertrophic cardiomyopathy. Proc Natl Acad Sci U S A. 1995 Apr 25;92(9):3864-8. doi: 10.1073/pnas.92.9.3864.

  PMID: 7731997 BACKGROUND

• Thierfelder L, Watkins H, MacRae C, Lamas R, McKenna W, Vosberg HP, Seidman JG, Seidman CE. Alpha-tropomyosin and cardiac troponin T mutations cause familial hypertrophic cardiomyopathy: a disease of the sarcomere. Cell. 1994 Jun 3;77(5):701-12. doi: 10.1016/0092-8674(94)90054-x.

  PMID: 8205619 BACKGROUND

MeSH Terms

Conditions

Cardiomyopathy, Hypertrophic; Hypertrophy, Left Ventricular; Cardiomegaly

Condition Hierarchy (Ancestors)

Cardiomyopathies; Heart Diseases; Cardiovascular Diseases; Aortic Stenosis, Subvalvular; Aortic Valve Stenosis; Aortic Valve Disease; Heart Valve Diseases; Hypertrophy; Pathological Conditions, Anatomical; Pathological Conditions, Signs and Symptoms

Study Design

• Study Type: observational
• Sponsor Type: NIH

Study Record Dates

• First Submitted: November 3, 1999
• First Posted: November 4, 1999
• Study Start: February 1, 1999
• Study Completion: August 1, 2002
• Last Updated: March 4, 2008

Record last verified: 2002-08

Locations

US (1)