Figure 6.

. (A) Plasma CKMB levels of 4-8 week old TgNI-nmd or B6-nmd and adult (6–8 month) N4F1 Cmn-nmd and age-matched littermates. (B) Mean ventricular free-wall thickness of 5–8 week old nmd, N3-N5 generation Cmn-nmd and unaffected littermates. (C) No significant differences are observed in the total heart wet-weights of B6.CAST-Mnm-nmd, N3-N6 Cmn-nmd or controls. However, wet-weights of individual cardiac chamber walls (D) do reveal significant differences. (E) Significant elevations of mean P-wave ECG amplitudes are evident in mutant nmd hearts carrying either the neuron-specific TgNI-transgene or Cmn cardiac modifiers compared to unaffected littermates, *p = 0.002 and **p = 0.009. (F) Derived cardiac functional parameters in B6-nmd mice and N3F1-N4F1 generation carriers of cardiac modifiers versus sib-controls (dLVv = left ventricular volume at diastole; sLVv = left ventricular volume at systole; EF = ejection fraction; FS = fractional shortening; SV = stroke volume; CO = cardiac output).