You are presented with a paragraph from a COVID-19 literature. Classify the topics of this piece of text by choosing from the following categories:

- Epidemic Forecasting: The content relates to predictions about the spread of COVID-19.
- Treatment: The paragraph discusses therapeutic methods or medication for COVID-19.
- Prevention: The content covers measures to prevent the spread of COVID-19.
- Mechanism: The paragraph explains the biological mechanisms of the virus.
- Case Report: The content is a report of a COVID-19 case.
- Transmission: The paragraph discusses how COVID-19 is transmitted.
- Diagnosis: The content is about diagnosing COVID-19 in individuals.

Your classification should be provided as an element within a JSON array. The array should be formatted with topics enclosed in double quotes and separated by commas, following the JSON format, for example: ["Topic1", "Topic2", ...]. Include all applicable topics within the array. Your output should be a valid JSON array, and no additional text should be included in your response.

Article:

OBJECTIVES: This study sought to describe expected changes in a mirror-image prone electrocardiogram (ECG) compared with normal supine, including a range of cardiac conditions. BACKGROUND: Unwell COVID-19 patients are at risk of cardiac complications. Prone ventilation is recommended but poses practical challenges to acquisition of a 12-lead ECG. The effects of prone positioning on the ECG remain unknown. METHODS: 100 patients each underwent 3 ECGs: standard supine front (SF); prone position with precordial leads attached to front (PF); and prone with precordial leads attached to back in a mirror image to front (PB). RESULTS: Prone positioning was associated with QTc prolongation (PF 437 +/- 32 ms vs. SF 432 +/- 31 ms; p < 0.01; PB 436 +/- 34 ms vs. SF 432 +/- 31 ms; p = 0.02). In leads V1 to V3 on PB ECG, a qR morphology was present in 90% and changes in T-wave polarity in 84%. In patients with anterior ischemia, ST-segment changes in V1 to V3 on supine ECG were no longer visible on PB in 100% and replaced by an R wave in V1. Bundle branch block (BBB) remained detectable in 100% on PB, with left BBB appearing as right BBB on PB in 71% and QRS narrowing with qR in V1 for right BBB. ST-segment/T-wave changes in limb leads and arrhythmia detection were largely unaffected in PB. CONCLUSIONS: As expected, the PB ECG is unreliable for the detection of anterior myocardial injury but remains useful for ST-segment/T-wave abnormalities in limb leads, BBB detection, and rhythm monitoring. The prone ECG is a useful screening tool with diagnostic utility in COVID-19 patients who require prone ventilation.
["Diagnosis", "Treatment"]