[This corrects the article on p. e17901 in vol. 6.].

BACKGROUND The cardiac myocyte t-tubular system ensures rapid, uniform cell activation and several experimental lines of evidence suggest changes in the t-tubular system and associated excitation-contraction coupling proteins may occur in heart failure. METHODS AND RESULTS The organization of t-tubules, L-type calcium channels (DHPRs), ryanodine receptors (RyRs) and contractile machinery were examined in fixed ventricular tissue samples from both normal and failing hearts (idiopathic (non-ischemic) dilated cardiomyopathy) using high resolution fluorescent imaging. Wheat germ agglutinin (WGA), Na-Ca exchanger, DHPR and caveolin-3 labels revealed a shift from a predominantly transverse orientation to oblique and axial directions in failing myocytes. In failure, dilation of peripheral t-tubules occurred and a change in the extent of protein glycosylation was evident. There was no change in the fractional area occupied by myofilaments (labeled with phalloidin) but there was a small reduction in the number of RyR clusters per unit area. The general relationship between DHPRs and RyR was not changed and RyR labeling overlapped with 51±3% of DHPR labeling in normal hearts. In longitudinal (but not transverse) sections there was an ∼30% reduction in the degree of colocalization between DHPRs and RyRs as measured by Pearson's correlation coefficient in failing hearts. CONCLUSIONS The results show that extensive remodelling of the t-tubular network and associated excitation-contraction coupling proteins occurs in failing human heart. These changes may contribute to abnormal calcium handling in heart failure. The general organization of the t-system and changes observed in failure samples have subtle differences to some animal models although the general direction of changes are generally similar.

BACKGROUND: An increasing number of patients aged 80 years and over are being considered and accepted for cardiac surgery. AIM: To review the experience of surgery in this elderly group of patients at our institution. METHODS: Hospital records of octogenarians undergoing surgery between January 1995 and September 1998 were reviewed and follow-up was obtained by general practitioner (GP) and patient questionnaires. RESULTS: Thirty-seven patients underwent cardiac surgery. The mean age was 82.8+/-1.4 years (range 80.8 to 86.2 years). Twenty-three (62%) were male. All were independent pre-operatively with severe symptoms and minor co-existing morbidity. All operations were urgent except two (emergency). Twenty patients (54%) had isolated coronary surgery, six (16%) aortic valve replacement alone, and 11 (30%) combined surgery. There were four (11%) early deaths and five (14%) peri-operative neurological events. The mean duration of post-operative intensive care stay was 2.4+/-3.9 days (range 0.05 to 16, median 1.0) and post-operative hospital stay 14.0+/-13.9 days (range 0 to 79, median 11). At the time of follow-up (mean duration 20.0+/-11.2 months) two further patients had died (non-cardiac). Twenty-six of the 31 survivors were living at home (23 independently), one with relatives, and four in residential care. Their cardiac symptoms were well controlled. The GPs of all hospital survivors, and all surviving patients themselves, felt that cardiac surgery had been beneficial. CONCLUSIONS: Cardiac surgery in the very elderly has been reserved for those with severe disease or symptoms and little co-morbidity. Early mortality is higher than for the general population undergoing cardiac surgery, but post-operative resource use is acceptable and the intermediate-term outcome for survivors is good.