Table 6. The incidence of pre-existing conditions in 58 snorkellers and the associated disabling injuries in the fatal incidents. CVA = cerebrovascular accident; IHD = ischaemic heart disease; IPO = immersion pulmonary oedema; SAH = sub-arachnoid haemorrhage .
| Condition | n (%) | Disabling injury |
| Respiratory | ||
| Asthma | 1 (1.7) | asphyxia |
| Cardiac | ||
| Arrhythmia | 9 (15.5) | cardiac (8), unknown (asphyxia? IPO?, 1) |
| IHD (diagnosed) | 22 (37.9) | cardiac (19), unknown (cardiac? asphyxia?, 3) |
| IHD (undiagnosed) | 6 (10.3) | cardiac (5), asphyxia (1) |
| Valvular heart disease | 3 (5.2) | cardiac (1), SAH (1), unknown (1) |
| Cardiomyopathy | 1 (1.7) | cardiac |
| Other | ||
| Drug/alcohol abuse | 4 (6.9) | cardiac (3), asphyxia (1) |
| CVA | 3 (5.2) | cardiac (3) |
| Diabetes | 3 (5.2) | cardiac (3) |
| Epilepsy | 3 (5.2) | asphyxia (3) |
| Hypertension only | 3 (5.2) | cardiac (3) |