Cardioplegia and Cardiac Function

................................................................................................... 7 LIST OF ORIGINAL ARTICLES .................................................................. 9 ABBREVIATIONS ......................................................................................... 10 INTRODUCTION ........................................................................................... 11 Myocardial protection.................................................................................................... 11 Warm and cold continuous blood cardioplegia ............................................................. 15 Simultaneous antegrade-retrograde blood cardioplegia................................................. 16 Intermittent warm blood cardioplegia............................................................................ 16 Measurements of cardiac function................................................................................. 17 Measurements of cardiac function using mechanical function indices ......................... 19 Heart rate and cardiac function...................................................................................... 23 Segmental and global left ventricular volumes ............................................................. 23 AIMS OF THE STUDY.................................................................................. 25 MATERIALS AND METHODS .................................................................... 27 Anaesthesia and surgical procedures (study I-V) .......................................................... 27 Data acquisition ............................................................................................................. 30 Data analysis and calculations ....................................................................................... 30 Calculationsstudy IV ................................................................................................... 31 Myocardial water content; Troponin T– study II and III ............................................... 32 Experimental protocols.................................................................................................. 32 Statistical analysis.......................................................................................................... 34 RESULTS........................................................................................................ 35 Results study I-III Cardioplegia studies....................................................................... 35 Results study IV Global vs. segmental volumes ......................................................... 39 Results study V Heart rate vs. cardiac function. ......................................................... 43 DISCUSSION.................................................................................................. 47 Cardioplegia studies The model .................................................................................. 47 Is continuous warm cardioplegia better than cold cardioplegia?................................... 48 Cardioplegic flow .......................................................................................................... 49 Is it safe to give antegrade and retrograde cardioplegia simultaneously?...................... 49 Should warm intermittent cardioplegia be used? .......................................................... 50 Statistical considerations ................................................................................................................ 51 Clinical implication ....................................................................................................... 52 How much global volume inform is gained .................................................................. 53 from a cm thick mid-cardiac volume segment? Cardiac function indices vs. heart rate........................................................................... 54 Pressure-volume loops vs. heart rate ............................................................................. 56 Conclusions and practical consequenses of study V ..................................................... 58 The conductance catheter method and its limitations .................................................................. 59 CONCLUSIONS ............................................................................................. 61 ACKNOWLEDGEMENTS............................................................................. 63 REFERENCES ................................................................................................ 65