Adv EP Lesson 6 - Complications

layers of the heart out to in

pericardium, epicaridium, myocardium, endocardium

pericardium

• Layer of connective tissue (pericardial sac) filled with lubricating fluids (serous fluids) to reduce friction and protects the heart

epicardium

• Outside layer of the heart and connects to pericardium.  Composed of fat and connective tissue.   Vessels that run through are responsible for delivery of oxygen to the cardiac tissue

myocardium

• Thick, muscular layer that generates the contractions that control the pumping of the heart

endocaridum

• Lines the chambers of the heart

pericardial sac

composed of the thin visceral pericardium which consists of a single layer of cells adherent to the cardiac epicardium and the thicker, fibrous parietal pericardium composed of collagen and elastin which is adherent to the lungs, diaphragm, sternum, great vessels, and other mediastinal structures surrounding the heart.

pericardial effusion

to the accumulation of fluid in the pericardial sac surrounding the heart which can lead to tampanade

tamponade

pressure on the heart due to build up of fluid in the pericardial space. 

pericardial effusion side effects

pericardium stretches out to accomodate bigger volumes of fluid wihout compressing heart leading to shortness of breath, chest pain, and compression of near structures

beck’s triad

low BP

distension of jugular veins

muffled heart sounds

acute pericardial tamponade

sudden fluid acumulation and pericardium can’t adjust so a dramatic increase in pressure inside pericaridal sac

causes of acute pericardial tamponade

chest trauma, ruptured aorta, ruptured of ventricle after a heart attack

causes of pericardial effusion in EP lab

1. Misdirected transseptal punctures either with punctures performed too posteriorly exiting the RA into the pericardium before entering the LA or punctures exiting the LA via the roof, LAA, or the lateral LA wall

2. Steam pops during RF ablation, and 

   1.  Mechanical perforation with catheter manipulation.

warning signs for pericardial effusion/tamponade in EP lab

1. Chest Pain if the patient is awake

2. Hypotension that could be sudden

3. Unexplained increase in heart rate

4. Still silhouette of the heart borders on fluoroscopy

5. Evidence of pericardial effusion on ICE, TEE or TTE

phrenic nerve injury can occur from what during PVI

RF and Cryo

what tech is most prone to phrenic nerve injury when compared to point by point ablation tech

balloon based tech

where in the heart is the risk higher for phrenic nerve injury

ablating the right superior pulmonary vein because of close proximity to the right sided phrenic nerve

where is the phrenic nerve

runs anterior to the right superior pulmonary vein

types of phrenic nerve injury and when it resolves

Transient Phrenic Nerve Injury (TPNI)- Resolves by end

Phrenic Nerve Palsy (PNP)- Not resolved after discharge but resolves by 12 months

Permanent Phrenic Nerve Injury (PPNI)- Does not resolve by 12 months

adjunctive methods to mitigating phrenic nerve damage

ICE, compound motor action potential, fetal heart monitor, venous pressure waveform

ICE method for mitigating

place ICE at liver to visualize diaphragm

at the first sign of decrease or loss of diaphragmatic contractions, immediately stop the ablation

compound motor action potential method for mitigating

use surface ECG leads and place along the diaphragm

immediately stop the ablation if CMAP amplitude decreases > 30-35%

fetal heart monitor method for mitigating

place across patient’s chest to detect diaphragmatic contraction

after hearing a decrescendo pitch, stop ablation

venous pressure waveform method for mitigating

femoral venous pressure waveforms are monitored using a standard pressure transducer to evaluate the strength of diaphragmatic contraction

what is a known complication of AP ablation

esophageal injury

reported rate of atrioesophageal fistula with arctic front advance

less than 1 out of 25000

strategies to minimize the risk of esophageal injury

reducing power/force/time of RF delivery on the posterior wall, using luminal esophageal temperature (LET) monitoring, use of a proton pump inhibitor, and avoiding energy delivery over the esophagus.

atrioesophageal fistula

an abnormal connection between the esophagus and the LA

thermal injury to endothelial cells of esophagus and/or damage to eophageal arteries causing ischemic necrosis of mucosal layers

symptoms of atrioesophageal fistula

Fever, rigors, fatigue, malaise, chest discomfort, dysphagia, N/V, hematemesis, neurological symptoms

diagnosis of atrioesophageal fistula

CT Scan with oral or IV contrast or MRI

treatment of atrioesophageal fistula

surgical intervention

esophageal ulcer of anterior wall

esophageal pericardial fistula

atrial esophageal fistula

ways to mitigate AE fistula

Monitor esophageal temperatures during RF (ablation terminated with a 1^oC rise in temperature of the esophageal temperature probe) and cryo ablation procedures (Medtronic physicians consensus suggests stopping ablation if esophageal temperature drops lower than 25^oC)

• Low-flow irrigation with lower RF energy delivery

• Mechanical esophageal deviation 

• Pharmacologic prophylaxis with proton pump inhibitors (PPI) or histamine H2 receptor blockers. 

stroke and transient ischemic attack

possibility due to left sided ablations

with catheter ablation the source of stroke is mainly

embolic where the stroke is outside the brain and mainly the heart

thromboembolism

obstruction of a blood vessel by a blood clot that has become dislodged from another site in the circulation

thromboembolism occurrence

occur within 24 hours of the ablation procedure

sources of thromboembolism during ablation

• Stationary sheaths positioned in the left atrium

• Char formation at the tip of RF ablation catheter and at the site of ablation

• Disruption of thrombus located in the atrium prior to  the ablation procedure and 

  • electrical cardioversion (cardioversion is the delivery of energy that is synchronized to the QRS complex to return the heart to normal sinus rhythm)

mitigating risk of thrombus formation in the LA

• Detailed pre-procedural imaging ensuring no thrombus or clot in the left atrium

• Strict anticoagulation protocol- Heparin is administered before transseptal access and ACT > 300 seconds is maintained

• Meticulous attention to sheath management

  • Careful control of RF energy to minimize char formation 

clot

air embolism cause

from introduction of air via the transseptal sheath

mitigating risk of air embolism

• Minimize risk of air emboli by prepping all catheters and sheaths used in the procedure properly. 

• It is important to remove all guide wires and sheaths slowly to minimize vacuum effect. 

  • All infusion lines are monitored closely for any air bubbles. Sheath exchanges also can be minimized

asymptomatic cerebral emboli

an occlusion of a blood vessel in the brain due to an embolus that does not result in any acute clinical symptoms and is therefore "silent"

complication with point by point RF and cryo during PVI

PV stenosis

PV stenosis

blockage of the pulmonary veins that bring oxygenated blood from the lungs to the heart

RF risk of PV stensosi

ablation close to PV orfices and/or within the PVs, with a 5.6 fold higher incidence in comparison with antral ablation.

cryo risk with PV stenosis

Ensuring the balloon is positioned at the antrum of the vein and not deep seated is a good practice to prevent pulmonary vein stenosis from occuring.

proximal seal technique

cryoballoon technique for preventing PV stenosis, ensures antral positioning of the cryoballoon

coronary artery spasm

a temporary constriction of the muscles in the wall of the artery.

spasm can reduce or block the blood flow to part of the heart. 

what were shown in PFA when delivered in proximity to the coronary arteries?

coronary artery spasms

what happened when pfa energy was applied for cavotricuspid isthmus ablation? how was it relieved?

provoked severe vasospasm

intracoronary nitroglycerin

what is subclavian access used for

implanting cardiac pacemakers

vascular access complication

includes development of a hematoma, arteriovenous (AV) fistula, or pseudoaneurysm. 

causes of vascular complications

• Number and size of venous sheaths used

• Insertion of arterial pressure line

  • Intense anticoagulation management before, during and after an EP procedure

access site complications

groin hematoma, retroperitoneal bleed, Femoral Pseudoaneurysm, Arteriovenous fistula

retroperitoneal bleed treatment and symptons

When the posterior arterial wall is punctured, blood can spread into the retroperitoneal space. The retroperitoneal space is the area that lies between the sublumbar muscles and the peritoneum

Fluid resuscitation.  Reversal of anticoagulation.  Vascular surgery if hemodynamic instability continue

hypotension, drop in hematocrit, Flank/abdominal/back pain but won’t discern during procedure

groin hematoma and treatment

pool of mostly clotted blood that forms in the groin. A hematoma is usually caused by a broken blood vessel that was damaged at the groin site during catheter access

Ultrasound guided compression. Usually resolve spontaneously over time. Rarely surgical removal or evacuation of blood in hematoma is necessary

Arteriovenous fistula and treatments

an abnormal connection between an artery and a vein. Usually occurs as a complication when access attempt goes through the vein and artery and creates a connection between the two.

compression, possible surgery

Femoral Pseudoaneurysm

esults from an injury to your blood vessel wall (usually an artery). Blood pools in a small sac attached to one side of the artery. Unlike an aneurysm, a pseudoaneurysm only includes one or two layers of the arterial wall and usually follows interventional procedures usually follow femoral arterial access.

compression, thrombin injection, possible surgery

prevention of groin complications

Use of ultrasound during groin access

While using large sheaths predilating the veins before accessing the vein with the large sheath

Seldinger technique for venous access

Seldinger technique

to obtain safe access to central vein. The desired vessel is punctured with a sharp hollow needle, syringe is detached and guidewire is advanced through the lumen of the needle, and then the needle is withdrawn.

how do vagal responses occur

close proximity of the ganglionic plexi to the pulmonary veins. Ablating the ganglionic plexi can sometimes lead to vagal responses.

what happens when vagal responses arrise

Temporary ventricular pacing is performed