Sandbox:Sara Haddadi

1. Sara Haddadi MD, Miami FL

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Classification of Infra-Hisian Block

Types of Infra-Hisian Block	Sub-type
Type 2 second degree heart block (Mobitz II)	_
Left bundle branch block	Left anterior fascicular block
Right bundle branch block	_

Covid19. [1] References

6/20/2020

Acute Coronary Syndromes

Pathophysiology

The mechanism of COVID-19 cardiovascular injury has not been fully understood and is likely multifactorial.

• SARS-CoV-2 virus attaches to ACE 2 protein for ligand binding before entering the cell via receptor-mediated endocytosis.
  • Based on single-cell RNA sequencing more than 7.5% of myocardial cells have positive ACE2 expression. This protein can mediate the entry of SARS-CoV-2 and result in direct cardiotoxicity.
• The cytokine release caused by the virus may lead to vascular inflammation, plaque instability, myocardial inflammation, a hypercoagulable state, or direct myocardial suppression.

Pathological changes:

• In the level of cardiac tissue: minimal change to interstitial inflammatory infiltration and myocyte necrosis
• In the level of vasculature: micro-thrombosis and vascular inflammation

ST-Elevation MI (STEMI)

A US model from 9 major centers showed a 38% drop in total STEMI activations during the COVID-19 pandemic. There is a 40% reduction noted in Spain as well. there was also a delay between the first presentation to a medical encounter up to 318 min. This is important since COVID-19 can potentially be a cause of STEMI through microthrombi, cytokine storm, coronary spasm, or direct endothelial injury.

• Potential etiologies for the reduction in STEMI PPCI activations:
  • avoidance of medical care due to social distancing or concerns of contracting COVID-19 in the hospital
  • STEMI misdiagnosis
  • increased use of pharmacological reperfusion due to COVID-19

It is very important to realize if patients' anxiety is the reason behind decreasing the presentation of STEMI to U.S. hospitals.

• Treatment of STEMI & COVID-19: The specific protocols for the treatment have been evolving. Early recommendations showed intravenous thrombolysis as first-line therapy for STEMI patients with confirmed COVID-19 since most hospitals do not have protected cardiac catheterization labs.

Signs and Symptoms

The signs and symptoms of acute coronary syndrome include:

• Chest pain

• Substernal chest pain
• Occurs at rest or exertion
• Radiation to neck, jaw, left shoulder and left arm
• Aggravated by physical activity and emotional stress
• Relieved by rest, nitroglycerin or both

• Chest discomfort described crushing, squeezing, burning, choking, tightness or aching
• Dyspnea
• Diaphoresis
• Nausea and vomiting
• Fatigue
• Syncope

Treatment

In patients with ACS, and COVID-19 treatment should follow the guideline of the updated Society for Cardiovascular Angiography and Interventions guidelines.