ST segment depression and ventricular fibrillation in a dog after contrast agent administration

Abstract

An 11-year-old Toy Poodle underwent a computed tomography examination with contrast (iohexol) enhancement under anesthesia. Heart rate and R-wave amplitude on electrocardiogram (ECG) increased 2.5 minutes after iohexol administration, and end-tidal carbon dioxide decreased to 12 mmHg. A progressive ST segment depression was observed on ECG. Subsequently, the ECG waveform changed to ventricular fibrillation. However, spontaneous circulation returned following cardiopulmonary resuscitation. Myocardial ischemia or anaphylactic shock was suspected in the dog, which explains the ST segment depression observed on ECG. When performing radiological examinations with a contrast agent, the ECG waveform changes, such as an increase in heart rate, R-wave amplitude, or ST segment depression, should be carefully monitored. This might enable early detection of cardiac dysfunction and the ensuing cardiac arrest in dogs.

Ventricular fibrillation in a dog with refractory hyperkalaemia due to uroabdomen following extradural anaesthesia

“…A significant reduction in preload would have likely incited myocardial ischaemia, indicated by ST depression, as in this case, but also elevation in dogs. Myocardial ischaemia is frequently associated with VF and probably contributed to the uncommon arrest rhythm observed here 3,26 …”

“…Myocardial ischaemia is frequently associated with VF and probably contributed to the uncommon arrest rhythm observed here. 3,26 Clinical assessment of volume status is challenging. Significant reduction in heart rate and increase in blood pressure in response to fluid challenges are often utilised, but mean arterial pressure is a late indicator of poor cardiac output.…”

Retrospective evaluation of the ST segment electrocardiographic features in 180 healthy dogs

“…Historically, poor attention has been paid by veterinary cardiologists to an important component of ventricular repolarisation, namely the ST segment, whose interpretation is currently performed almost empirically in small animal practice. This knowledge gap can have relevant clinical consequences, as it may not allow for the early identification of ventricular repolarisation abnormalities expressed in the form of ST segment changes that may arise from myocardial injury due to cardiac (Tilley 1992b, Davainis et al 2004, Sleeper et al 2015, Santilli et al 2018b, Lekane et al 2020) and extracardiac diseases (Tilley 1992b, Dvir et al 2004, Surachetpong et al 2016, Santilli et al 2018b, Pugliese et al 2020, the administration of drugs and medium contrast agents (Tilley 1992b, Khurana et al 2014, Santilli et al 2018b, Tamogi et al 2020) and electrolyte abnormalities (Tilley 1992b, Santilli et al 2018b.…”

“…2018b , Tamogi et al . 2020 ) and electrolyte abnormalities (Tilley 1992b , Santilli et al . 2018b ).…”