#11. What to look at in COVID and ECG monitoring

Hi, I am Dr. Nicola Cosentino. Welcome to this podcast series on COVID-19 and ECG, sponsored by GE Healthcare. Today’s topic will be on what to look at in the ECG of COVID-19 patients and which patients with COVID-19 should be continuously monitored.

SARS-CoV2 infection may cause acute myocardial injury and this injury may be associated, in turn, with ECG alterations. Many ECG alterations and many kind of arrhythmias have been described in COVID-19 patients. Yet, there are some ECG patterns that must be closely monitored and, if detected, identify very-high risk COVID-19 patients, as these ECG acute changes mainly reflect the ongoing left ventricular ischemia/stiffness and/or right ventricular distention/dysfunction.

Notably, the following alterations are the ones most closely associated with a worse prognosis, in terms of in-hospital mortality and need of invasive mechanical ventilation:

• de-novo T wave inversion (especially if involving several leads)
• new ST-segment deviation >0.5 mm, new intra-ventricular conduction delay  (i.e. LBBB or RBBB) or QRS prolongation more than 25% from baseline
• QTc interval is >500 msec (or any acute increase of >60 msec or >25% from baseline)
• de-novo right bundle branch block and right axis deviation.

On the other hand, although all types of arrhythmias have been observed in hospitalized COVID-19 patients, there are some that, again, are most strongly associated with an ominous clinical outcome. These are:

• de-novo atrial fibrillation with rapid ventricular rate
• new atrio-ventricular block
• torsades de pointes
• sinus tachycardia with new left bundle branch block.

Regardless of the underlying arrhythmic disorder, faster heart rates are always associated with a more complicated in-hospital clinical course, by mirroring the hemodynamic and respiratory impairment.

Therefore, a 12 lead-ECG should be performed in all patients at admission, and at day 3 and 7 of hospitalization and before discharge. Moreover, ECG should be performed anytime there is an increase in troponin and/or brain natriuretic peptide circulating level or if the patient experiences chest pain or dyspnea, in order to exclude the presence of ECG ischemic alterations.

Furthermore, due to the high risk of serious arrhythmias, potentially life-threating, there are some COVID-19 patients that need to be continuously monitored by the ECG with the aim to rapidly detect any complex arrhythmias and to identify early any progressive clinical deterioration.

So, which COVID-19 patients should be continuously monitored?

• Patients admitted to ICU need to be continuously monitored
• For those not admitted to the ICU, continuous ECG monitoring for at least 48, and if possible, 72 hours, should be reserved for
  • hospitalized patients with pre-existing cardiovascular disease
  • those having elevation in cardiac biomarkers, that is, troponin and/or brain natriuretic peptide
  • those with de novo ECG changes, especially if de novo wide QRS complex or de-novo diffuse T wave inversion, or prolonged QTc interval
  • those with severe COVID-19 disease, in particular if dyspnea, tachypnea, and hypoxia persist after 7-10 days of symptoms’ onset, despite treatment

There are still some subsets of COVID-19 patients who should be continuously monitored, despite not meeting the prior criteria. In particular:

• Those with bradycardia (heart rate <40) or tachycardia (heart rate >120 bpm)
• Those with ventricular arrhythmia (>6 VEB/min, non-sustained ventricular tachycardia, sustained ventricular tachycardia) and/or sustained supraventricular arrhythmia
• Those with de-novo left ventricular disfunction (left ventricular ejection fraction <50%, especially if <40%) and/or de-novo right ventricular distention or dysfunction
• Those with altered mental status or severe electrolyte abnormality
• Those in whom chest CT scan shows >30/40% lung involvement.

There are two additional electrocardiographic issues that deserve attention in COVID-19 patients. One critical issue in COVID-19 patients is represented by QTc prolongation, as it can lead to polymorphic ventricular tachycardia (torsades de pointes [TdP]). Patients with a baseline QTc >500 msec (>550 msec if bundle branch block or ventricular pacing) are at risk of developing TdP or sudden death. Briefly, the following steps are required to reduce the risk of drug-induced TdP:

1. Identify non-modifiable risk factors associated with QTc prolongation (congenital LQTS, QTc prolongation on known QT prolonging drugs, female sex, age >65 years, structural heart disease, renal impairment, and liver impairment)
2. Identify and correct modifiable risk factors in all patients (correct hypocalcaemia, hypokalaemia, hypomagnesaemia, stop non-necessary concomitant use of QTc-prolonging medications, and avoid bradycardia [the concomitant use of beta-blockers, CCBs, ivabradine and digoxin should also be evaluated])
3. Perform a baseline ECG (12-lead or single strip, depending on resource availability) before initiating therapy;
4. Perform ECG once on treatment (after 1 day if no risk factors are present and after 4 hours of treatment if risk factors or prolonged QTc are known).

If the patient has a QTc >500 ms or shows an increase in QTc >60 ms (or >25%), switching to a drug with lower risk of QTc prolongation, reduction of the administered dose, or continuing treatment plan are the options to consider. Close surveillance of QTc interval (preferably including telemetry for arrhythmia monitoring) and electrolyte balance are mandatory.

Finally, Brugada syndrome may represent an important issue in COVID-19 patients and the main concern is fever-triggered malignant ventricular arrhythmia. COVID-19-induced fever may uncover the type 1 Brugada pattern and lead to symptomatic Brugada syndrome in previously unsuspected cases. Therefore, in all COVID-19 patients with Brugada syndrome, fever should be aggressively treated with paracetamol. Continuous ECG monitoring should be considered if antipyretic therapy is ineffective, and the temperature remains >38.5C in higher-risk Brugada syndrome patients (those with sodium channel mutation carrier, < 26-years old > 70-years old, spontaneous and/or known fever induced type-1 ECG pattern).

In conclusion, 12-lead ECG and continuous ECG monitoring are critical aspects in the treatment of COVID-19 patients, as they may help to early identify very-high risk patients who may deserve a close follow-up and more intensive therapeutic strategies. And I believe that what we have learned during COVID-19 on the clinical benefit derived from ECG and continuous ECG monitoring may be translated to most acute illness and should be a lesson to keep always with us when we face critical patients.

Thank you for listening to this podcast on what to look at when ECG monitoring is implemented in COVID-19 patients. The next podcast of this series will be on ECG monitoring in non-cardiac areas.

References:

Sandau KE, Funk M, Auerbach A, Barsness GW, Blum K, Cvach M, Lampert R, May JL, McDaniel GM, Perez MV, Sendelbach S, Sommargren CE, Wang PJ; American Heart Association Council on Cardiovascular and Stroke Nursing; Council on Clinical Cardiology; and Council on Cardiovascular Disease in the Young. Update to Practice Standards for Electrocardiographic Monitoring in Hospital Settings: A Scientific Statement From the American Heart Association. Circulation. 2017 Nov 7;136(19):e273-e344.

Kochav SM, Coromilas E, Nalbandian A, Ranard LS, Gupta A, Chung MK, Gopinathannair R, Biviano AB, Garan H, Wan EY. Cardiac Arrhythmias in COVID-19 Infection. Circ Arrhythm Electrophysiol. 2020 Jun;13(6):e008719.

Task Force for the management of COVID-19 of the European Society of Cardiology. ESC guidance for the diagnosis and management of cardiovascular disease during the COVID-19 pandemic: part 2-care pathways, treatment, and follow-up. Eur Heart J. 2022 Mar 14;43(11):1059-1103.