ECCO: Assessing and Managing Aortic Aneurysm, dissection, and Repair; Carotid Artery Stenosis and Peripheral Vascular Disease, ECCO: CV Pt 2: Assessing and Managing Patients with Long QT Syndrome, Electrophysiologic Studies, Radiofrequency Ablation,…

What layer of the aorta is damaged in aneurysm and what structural differences occur

Middle layer

Structural matrix proteins are damaged and inflammatory process may also contribute

What structural matrix proteins

Elastin and collagen

How are aneurysms classified and kinds

By shape:

1. Fusiform

2. Saccular

Fusiform aneurysm is/looks like what

More common, bulges or balloons out on all sides of blood vessel

Saccular aneurysm

Saccular-shaped aneurysm bulges out only on one side

Other classification of aneurysms

Location

Locations of aortic aneurysms and which is more common

Abdominal are more common

Thoracic

Are small thoracic aneurysms typically symptomatic

No, they aren't compressing many structures

How is thoracic aneurysm diagnosed

If arterial segment is 50% greater than its normal diameter

Locations of thoracic aneurysms

Ascending aortic aneurysms

Aortic arch aeurysms

Descending thoracic aneurysms

Risks with ascending aortic aneurysms

Can extend to aortic valve annulus and as far as the innominate artery

Valve annulus can cause aortic insufficiency and affect the origins of the coronary arteries, leading to MI

What is affected by aortic arch aneurysms

Arteries branching off the arch

1. Innominate

2. Left common carotid

3. Left subclavian artery

Descending thoracic aneurysms start where

Beyond the left subclavian artery and can extend into the badomen

What arteries affected by descending thoracic aneurysms

Intercostal arteries, thus impacting perfusion to the spinal cord

Risk factors of ascending aortic aneurysm

Patients with connective tissue disorders such as Marfan syndrome

Risk factors of descending aortic aneurysm

Typically develop in elderly patients with HTN, lung disease, and diffuse atherosclerosis

S/S of AAA

Most are asymptomatic and discovered during another exam

1. Abdominal pulsation

2. Nausea

3. diminished extremity pulses

4. Low back pain

AAA Dx

Antero-posterior diameter of the aorta becomes greater than 3 cm

Where do 95% of AAA happen

Infrarenal segment

Where can AAA extend

From diaphragm to the iliac arteries. Renal and visceral arteries may be affected

Risk factors for AAA

1. Male

2. Family history

3. Advanced age

4. Cigarettes

5. HTN

6. Polycystic kidney disease and other renal diseases

7. Atherosclerosis and other vascular diseases

8. Known popliteal aneurysms

9. Marfan syndrome

What is used to Dx aortic aneurysms

1. CXR

2. CT

3. TEE

4. US

5. Peripherial angiography

CXR showswhat

Increased aortic diameter or tracheal deviation

CT scan shows what

Assess diameter of aortic lumen, wall thickness, aneurysm size, mural thrombi, origin, and extent of the aneurysm

Annulus definition

Ring shaped structure

TEE shows...

Dilation in the aortic root, proximal ascending aorta, or descending thoracic aorta, or aortic regurgitation from aortic root dilation

US shows...

Monitor the progression of aneurysms over time and to assess peripheral and cerebrovascular blood flow and flow velocity

Peripheral angiography shows

Used to define the anatomy and severity of lesions and most suitable interventions

What two medications for aneurysms

1. Beta blockers

2. ACE inhibitors

What S/S would indicate aortic repair is necessary

1. Back pain

2. Abdominal pain

3. Hypotension

4. Pulsatile abdominal mass

What surgical procedures done for Ascending thoracic aneurysm

Treated based on:

Size

Growth

Or symptoms

Need initial cardiac catheterization to determine if CABG is required to treat coexisting CAD, which is done at the same time as aneurysm resection and repair

What surgical procedures for descending thoracic aneurysm

Based on size and symptoms

First check for CAD. If present, pre-op treatment to reduce CV risk associated with the surgery or procedure

When is end-vascular grafting indicated

Descending thoracic, thoracic-abdominal, and abdominal aneurysms

What approach is preferred for infrarenal AAAs and patients with severe cardiopulmonary risk factors

Endovascular grafting

What assessments for aortic dissection

Distal pulses in all extremities

PMH including medications

In thoracic dissection, BP differences between arms can indicate what

Greater than 20 mmHg could indicate dissection of the subclavian, innominate, brachial, or axillary arteries

Where is the innominate artery

The brachiocephalic artery (labeled innominate) ... the brachiocephalic artery divides into the right common carotid artery and the right subclavian artery. ...

What causes dissection

Can be alone or in presence of aneurysm

May also be caused by traumatic injury

Risk factors for aortic dissection

1. Aging

2. HTN

3. Atherosclerosis

Aortic dissection pathophys

Separation of layers within the aortic wall, blood enters tear creating false channel/lumen. Blood then extends proximally or distally

Mortality rate of rupture

90%

Ascending aorta dissection symptoms

1. Chest pain (MI may occur if dissection reaches the coronary ostiAa

2. Signs of decreased CO from acute aortic regurgitation

3. Tamponade if dissection results in bleeding into pericardium

Coronary ostia

Coronary Openings that the right and left coronary arteries arise through

Aortic arch symptoms

1. Differences in upper extremity BPs

2. AMS

3. Signs of stroke

4. Pain extending into the neck or jaw

Abdominal aorta S/S

Abdominal or plank pain and tenderness

2. Decreased lower extremity blood pressures and pulses

BP goal for aortic dissection

MAP 60-65

Short-acting beta blocker example

Esmolol

Meds for dissection

Short acting beta blocker

AE-I like enalapril or other vasodilator like nitroprusside

If beta blocker contraindicated

Dihydropyridine CCBs such as nicardipine

Combination alpha and beta blocker

Combination alpha and beta blocker example

Labetalol

Classifications of dissections

A: acute or chronic dissections involving the ascending aorta, and require surgical repait

B: Dissections are located in the descending thoracic and abdominal aorta. They begin distal to the left subclavian artery

Type A meds

Manage HTN to avoid rupture

Type A surgery

Mortality approximately 15-20% and therefore, aggressive surgical treatment in the elderly is controversial

Type B meds

Usually treated medically as patients are higher surgical risk candidates due to advanced age, extensive atherosclerotic disease, and existing comorbidities

Type B surgery

Limited to complicated dissections, which include patients with persistent pain, uncontrolled HTN, or evidence of expansion or rupture

Also indicated with circulatory compromise to visceral, renal, or lower extremity vessels and resultant organ ischemia, or if a chronic dissection reaches 5.5-6.0 cm diameter

Type A complications

1. Cardiac tamponade d/t rupture, the most common cause of death

2. Aortic regurgitation from retrograde dissection involving aortic valve or from aortic root dilation

3. MI from retrograde coronary artery dissection

4. Stroke or brachial artery compromise due to dissection causing hematoma

Descending aortic (type B) complications

1. Hemothorax d/t rupture into the intrapleural space

2. Parplegia or bowel ischemia due to compromise of arterial branches

Abdominal aortic (Type B) complications

2. Retroperitoneal bleeding due to rupture

2. Renal ischemia due to renal artery involvement

Endovascular repair used for what

Possibly for thoracic-abdominal and abdominal aneurysms

Endovascular graft complications

Leak into aneurysm

Follow-up imaging to detect leaks is required every 6-12 months. leaks typically occur in first year following endograft placement

Type A surgical approach

Median sternotomy

Portion of aorta with proximal intimal tear is resected and entrance to false channel is eliminated

Resected ends of aorta are re-approximated using a fabric graft

In aortic regurgitation, simultaneous aortic valve replacement may be done

In retrograde dissections, re-implantaion of the coronary arteries may also be necessary

Complications of type A surgery

Because distal false Chanel remains, at risk for future aneurysm

Risk for bleeding and MI in post-op period

Cross-clamping of the aorta during surgery may result in ischemia to spinal, mesenteric, or renal arteries

Type B surgery Procedure

Large thoracotomy incision and possible involvement of the diaphragm

Type B complications

Cross-clamping aorta may result in ischemia to spinal, mesenteric, or renal arteries and can lead to paresis or paralysis, ischemic colitis, or AKI

Leg ischemia or compartment syndrome may occur

patients may experience significant pain due to the thoracotomy approah

Open abdominal repair for AAA

Mid-line transabdominal approach or extra-peritoneal left flank incision

Pararenal and suprarenal aneurysms require aortic cross-clamping above the renal arteries

Complications of open abdominal repair for AAA

Increased risk for bleeding from the abdominal incision

2. Ischemia and/or acute kidney injury risk increases if the aorta was cross-clamped above the renal arteries

3. Increased incisional pain can cause atelectasis secondary to decreased diaphragmatic excursion

4. Repairs done above the level of the renal arteries have higher mortality

TIA Dx

Neurologic dysfunction that resolves completely within 1-2 hours, accompanied by neuroimaging that shows no evidence of infarction

Dx study for carotid stenosis

US

Angiogram

Computed tomography angiogram

Candidates for surgery with carotid stenosis

>60% stenosis may benefit from surgical endarterectomy to remove plaque

Alternatively can do carotid angioplasty

Most common meds that cause QT prolongation

1. Antidysrhythmics

2. Antibiotics

3. Antidepressants and antipsychotics

4. Antiemetics

Other causes of QT prolongation

1. Electrolyte abnormalities, especially hypokalemia or hypomagnesemia

2. Bradycardias or dysrhythmias resulting in frequent pauses in the rhythm

3. Acute subarachnoid hemorrhage or other acute neurological events

Normal QTc

0.44 or less

What is QTc

QT (interval) corrected for heart rate

What formula used for QTc

Bazett's formula

Bazett's formula

QTc= QT interval in seconds divided by the square root of R-R interval in seconds

Indications for cardioversion

1. Unstable SVT

2. Afib

3. A flutter

4. Unstable monomorphic Vtach

What patient preparation must be done for cardioversion

1. Ensure K and Mg or normal

2. If on anticoagulation, ensure they're within therapeutic range

3. Ensure chest is dry

4. Tell patient shock is painful

5. TEE may be done immediately prior to cardioversion to ensure atrial thrombus is not present

Electrode placement for cardioversion: Anterior-posterior placement

Left anterior precordial area and left posterior infrascapular area

Anterior placement

Second intercostal space to the right of the sternum and fifth intercostal space, midaxillary line to the left of the strernum

Electrode pad placement in patient with ICD or permanent pacemaker

Don't place over pulse generator

Steps of cardioversion

1. Charge defibrillator: Set energy level as ordered depending on rhythm

2. All clear

3. Discharge defibrillator

4. Evaluate rhythm

Normal energy for defibrillator in cardioversion

50-100 joules

Post-cardioversion steps

Assess hemodynamics

Provide O2

Monitor post-sedation recovery

Does cardioversion involve sedation

Yes

What happens to the heart during defibrillation

All cells in the heart depolarize simultaneously, allowing sinus node to resume function as normal pacemaker

Electrode pads vs paddles

Pads: allow fast shock delivery, can also be used emergently for EKG monitoring

Paddles: Rarely used, require conductive gel pads placed between the paddles and the skin to protect against burns. Exerts approximately 25 pounds of pressure to decrease transthoracic impedance and increase shock efficacy

Steps of defibrillation

1. Ensure EKG rhythm is visible on defibrillator monitor and sync feature is off

2. Set energy to desired joules and press charge button

3. All clear

4. Shck

5. Resumse CPR for two minutes before rhtyhm and pulse check. Continue emergency ACLS procedures as indicated by cardiac rhythm, BP, and LOC

What is an EPS

Electrophysiology Study

What do EPS reveal

Origin and conduction patterns of SVT and ventricular dysrhythmias and efficacy of antidysrhythmic medications

Pre-EPS care

1. Assess serum electrolytes

2. Adhere to provider orders to continue or dicontinue antidysrhythmic medications at specific interval

3. Ensure the patient is NPO for specific interval

Steps of EPS

1. Patient is sedated

2. Catheters into heart primarily through venous system

3. Electrical activity is recoreded from locations along the conduction system to determine activation patterns

4. Electrical stimuli are delivered to induce and/or terminate dysrhythmia

5. Medications may be given to determine efficacy in preventing dysrhythmia

Indications for radiofrequency ablation

1. Tachydysrhythmias associated with accessory pathways

2. Symptomatic drug-refractory SVT

3. Symptomatic AF not responding to medications

4. While less common, for frequent recurrent VT not responding to medications

Most common indication of radiofrequency ablation

SVT

What happens in RFA

Cauterizes a small area of endocardium

Alternative to RFA

Cryoablation: delivered through the catheter is cold, freezing the target tissue rather than cauterizing it

Pre-RFA

Need pregnancy test

Need evaluative EPS prior to RFA to determine mechanism and tissues involved in the tachycardia

RFA Steps

May be performed during EPS

Moderate-deep sedation

Catheter inserted via venous or arterial approach and positioned next to the selected tissue

Energy delivered through the catheter to produce necrosis as necrotic tissue unable to conduct electrical impulses, which prevents further episosdes of dysrhtyhmia

One unique sign of hypertensive crisis

Epistaxis

How is HTN crisis diagnosed

BP elevation with symptoms related to dysfunction in other body systems including:

CV, CNS, RENAL or retinas

HTN Crisis in CV system

1. chest pain

2. HF: dyspnea, S3 and/or S4 sounds, pulmonary edema

3. Hypertension after vascular surgery

4. Catecholamine excess (increased HR, RR, and glucose, peripheral vasoconstriction)