Table 1.
Heritability of electrocardiographic and heart rate variability phenotypes examined in the Framingham 100K project
| Phenotype | Acronym | Heritability sample | Original Exam | Offspring Exam | Adjustment* | Heritability† (SE) |
|---|---|---|---|---|---|---|
| Electrocardiographic phenotypes | ||||||
| QT sex-pooled | QTPOOL | 1951 | 11 | 1 | Age, RR, sex, cohort | 0.39 (0.04)† |
| QT men only | QTMEN** | 900 | 11 | 1 | Age, RR, cohort | 0.43 (0.08) |
| QT women only | QTWOMEN** | 1051 | 11 | 1 | Age, RR, cohort | 0.46 (0.04) |
| RR sex-pooled | RRPOOL | 1951 | 11 | 1 | Age, sex, cohort | 0.29 (0.04) |
| RR men only | RRMEN** | 900 | 11 | 1 | Age, cohort | 0.28 (0.08) |
| RR women only | RRWOMEN** | 1051 | 11 | 1 | Age, cohort | 0.31 (0.07) |
| PR sex-pooled | PRAdjRRPOOL | 1950 | 11 | 1 | Age, RR, sex, cohort | 0.34 (0.04) |
| Heart rate variability phenotypes | ||||||
| SDNN sex-pooled | SDNNHRV | 747 | 18 | 3 | Age, heart rate, SBP, DBP, coffee & alcohol intake | 0.32 (0.09)† |
| Total power sex-pooled | TOTPWRHRV | 747 | 18 | 3 | Age, heart rate, SBP, DBP, coffee & alcohol intake | 0.41 (0.10)† |
| Low frequency/high frequency power sex-pooled | LFHFHRV | 747 | 18 | 3 | Age, heart rate, SBP, DBP, coffee & alcohol intake | 0.36 (0.10)† |
All phenotypes for ECG and HRV traits are shown (including pre-specified secondary traits not examined for this report), including covariates adjusted for in linear regression models. Heritability estimates were generated in the superset of individuals with phenotype values in families (n ≤ 1951 for ECG traits, n ≤ 747 for HRV traits). For electrocardiographic traits there were 1175 individuals with genotypes and for heart rate variability there were 548 individuals with genotypes in the 100K analyses. All results are publicly available at http://www.ncbi.nlm.nih.gov/projects/gap/cgi-bin/study.cgi?id=phs000007.
*Separate regression models were created by cohort and sex for ECG and HRV measures. †All heritability estimates <0.001.
**Prespecified secondary results in GWAS pipeline but not analyzed in this report (available at http://www.ncbi.nlm.nih.gov/projects/gap/cgi-bin/study.cgi?id=phs000007). QT and HRV heritability estimates are consistent with previous reports in largely overlapping sample [9,16].