Syncope

Question 1

Syncope

Answer 1

A transient loss of consciousness accompanied by a loss in postural tone, followed by a return to baseline function
- if no return to base line = SCD

• results from global hypo-perfusion to cerebral cortices
• is a symptom, must find out why it occurred

Most common age groups are 10-30 and >70 yr olds

Question 2

Pathophysiology of syncope

Answer 2

Usually results once a fall in systolic BP to <50mmHg or lower
- will return back to baseline afterwards however

Question 3

Neurally mediated syncope (reflex syncope)

Answer 3

• also called vasovagal syncope*
• most common cause of syncope and is benign

Mixed group of disorders w/ final pathway being hypotension, vasodilation and bradycardia

• increases parasympathetic tone And baroreceptors responses
• loss of sympathetic tone

Symptoms before passing out includes:

• prodromal symptoms
• dizzy/light head ness
• nausea/vomiting
• pallor
• ab pain

Patient regains consciousness quickly and is otherwise fine
- results in no increases in mortality

Question 4

Carotid sinus hypersensitivity

Answer 4

Type of reflex-mediated syncope

Results from external pressure at the carotid sinus where the carotid is extra sensitive

Includes the following possible reasons:

• shaving
• tight collar
• turning of the head
• coughing
• dedication/micturition
• swelling
• stressful situation syncope

Symptoms are the same as vasovagal and may also include possible asystole

NOT life threatening

Question 5

Orthostatic syncope

Answer 5

Syncope associated w/ drop in systolic BP (>20mmHg/>10mmHg) when changing position to standing up
- very common in elderly patients since the medications they are taking

Is an autonomic dysfunction and can also be induced by the following meds

• BBs
• CBBs
• nitros/ vasodilators

Possible physical reasons include:

• volume/blood loss
• major dehydration

May be life-threatening but depends

Question 6

How to test for orthostatic hypertension

Answer 6

Have patient lie down quietly for five minutes
- check BP

Have patient stand up quickly and check blood pressure after 3 minutes

If the patients 2nd BP measure decreases 20/10mmHg or more, they have orthostatic hypotension

Question 7

Serious causes for cardiac syncope

Answer 7

cardiac syncope is the most dangerous

1) Arrhythmias
- sinus node dysfunction (sick sinus, SA blocks)
- Stokes-Adams attack (syncope by heart block)
- A fib
- type 2 or 3rd degree heart blocks (leads to stokes-Adams
- tachyarrthmias

2) valvular diseases
- especially AS

• no prodromal symptoms will be present no warning signs

Question 8

Tachyarrthmias w/ cardiac syncope

Answer 8

Heart rate >200 can cause syncope
- caused by decreased diastolic filling leading to poor perfusion to carotid, hypotension and ischemia

tachyarrthmias are the most concerning for cardiac syncope

Question 9

Groups of patients that have increased chance of ventricular arrhythmias

Answer 9

Ischemic heart disease
- 3% of patients w/ MI will have a major syncopal episode(s)

Long QT syndrome

• mechanism PVCs that occur naturally
• defective sodium and potassium channels that leads to increase repolarization
• QTc >450msec is the norm (or greater than half the rate of RR interval)
• very predisposed to TdS
• is also very likely caused by hypokalemia or hypomagnesemia

Brugada syndrome

Cardiomyopathies
- especially HCM

Congestive Heart failure
- w/ <35% EF

WPW disease

Question 10

Romano ward vs jervell syndromes

Answer 10

Both are long QT syndromes

Jervell = presents w/ congenital deafness

Romano-ward = presents w/out congenital deafness

Question 11

WPW w/ atrial fibrilation/flutter

Answer 11

Dangerous since the ventricular rates will get above 300bpm

- will induce V. Fib or asystole if not treated

Question 12

Hypertrophic cardiomyopathy

Answer 12

Most common cause of sudden death of <35 year old males

Very genetic based w/ 60-70% of people having an affected family member
- autosomal dominant but effects men slightly more than women

Most common symptoms

• passed out w/ exercise or strenuous movements
• also proved to denaturation syncope
• EKG shows LVH
• always shows some level of angina w/ exercise
• septal hypertrophy will be common
• murmur is louder along left sternal border

Tx:

• surgical myomectomy
• ICD
• septal ablation

Question 13

Aortic stenosis w/ syncope

Answer 13

10% of patients w/ severe aortic stenosis will show syncope
- cardiac output will not increase w/ exercise as well (similar to HCM)

Presents w/ increased risk of atrial fibrillation due to stretched irritated SA node cells (left atrial enlargement will occur)
- not much of a risk for ventricular arrhythmias but can be induced by a fib

• # 1 cause is congenital bicuspid aortic valve*

Question 14

HF w/ syncope

Answer 14

Almost always occurs if the HF is presented w/ ejection fractions of <35%.

• increased risk of v fib
• requires ICD placement

Question 15

Other less common causes of cardiac syncope

Answer 15

Right atrial myxoma (obstruction of right atria)

PEs

Metabolic problems (specifically hypoglycemia)

Vascular emergencies

Question 16

What should you do when someone experiences syncope

Answer 16

1) lay them down (if they are not laying down)
- causes seizures if not

2) check breathing And pulses
3) call 911

Question 17

Evaluation of syncope

Answer 17

1) make sure the patient is stable

2) obtain a good history
- especially family history and what they were doing before

3) physical exam
- if new murmur is present w/ syncope that’s a bad sign

4) get 12 lead ECG
5) get labs based on history and physical exam
6) treat underlying problem

Question 18

What symptoms/signs make someone a high risk patient w/ syncope?

Answer 18

Angina/ palpation at time of syncope
- especially if it is still present

Abrupt syncope without warning signs

Exertional syncope

Abnormal ECG is found

• tachyarrthmias
• heart blocks (especially type 2, 3rd degree and new LBBB)
• prolonged QT interval
• delta wave
• LVH
• Brugada patterns

Family history of sudden death

Signs of hypoxia

Hematocrit is less than 30 and/or systolic blood pressure <90 mmHg

Question 19

Medications to avoid in QT syndromes

Answer 19

Class 1a cardiac drugs
- especially quinidine

Class 3 cardiac drugs

Azithromycin

Erythromycin

Cimetidine

Antidepressants

Antiemetics