CARDIAC

The Approach to Chest Pain

By differential diagnosis:

· Musculoskeletal

- Hx: incr pain with mvmt, trauma, also consider herpes zoster (pain in a dermatomal distribution), etc

- Dx: hx, pain reproducible with palpation (though some studies show this does NOT exclude cardiac CP)

- Rx: symptomatic, NSAIDs with costochondritis, possible role for antivirals in VZV

· GERD/PUD/Esophageal spasm

- Hx: assoc with burping, funny tastes, certain foods, pain worse with lying down, etc

- Dx: hx, can confirm with barium swallow studies, manometry, also consider H. pylori testing, etc

- Rx: H2-blockers, PPIs, ABx if H.pylori +, lifestyle mod (no late meals, avoid caffeine, avoid chocolate, etc)

· Esophageal tears (Mallory-Weiss)

- Hx: h/o emesis, often presents with hematemesis (but doesn’t have to), etc

- Dx: hx, can confirm with esophagogastroduodenoscopy (EGD)

- Rx: can heal with rest/conservative mgmt, may need surgical repair if severe; if hematemesis treat as upper GI bleed,

· Pulmonary embolus

- Hx: decreased mobility, h/o coagulation disorder, h/o malignancy, post-operative, etc

- Often presents with tachypnea, tachycardia, pleuritic CP, etc

- Dx: hx, contrast chest CT with PE protocol (need a peripheral IV in an upper extremity for adequate PE protocol chest CT), may use V/Q scan if contraindication to contrast (ie: allergy, ARF, etc), can see RV dilation on TTE

- Rx: anticoagulate (if your suspicion is high enough and/or pt is unstable, don’t wait for the test to start anticoag)

· Pneumothorax

- Hx: h/o thoracic procedures, appropriate body habitus (ie: tall) for spontaneous PTX, mech ventilation, severe bronchospastic/obstructive lung disease, c/o SOB, etc

- Dx: hx, possibly hypotension, possible tracheal deviation (tension PTX), look at a CXR

- Rx: chest tube (if tension pneumothorax, decompress with a needle in the 2^nd intercostal space at midclav line)

· Aortic dissection

- Hx: h/o weight lifting/exertion, appropriate body habitus (ie: Marfan’s), h/o syphilis, pain ‘tearing’ to the back

- Dx: hx, differential BP’s, possible to see mediastinal widening on CXR, but usually need a CT or MRI

- Rx: Type A (involves ascending Ao) -> surgery; Type B -> medical mgmt (aggressive BP ctrl, etc)

· Pericarditis

- Hx: h/o MI, viral illness, lupus, thoracic surgery, etc

- Dx: hx, rub (best heard supine), EKG shows diffuse PR depression and ST elevation, incr ESR/CRP, can see associated effusion or pericardial thickening on TTE, also consider CT scan

- Rx: Steroids, NSAIDs

· Cardiac Tamponade

Hx: trauma/penetrating wound, pericarditis

Dx: hx, pulsus paradoxus, distant heart sounds/elevated neck veins/hypotension (Beck’s Triad), low voltage EKG, electrical alternans on EKG, large cardiac silhouette on CXR, effusion on TTE

Rx: acutely give IVF, definitive treatment is pericardiocentesis

· Acute Coronary Syndromes (ACS)

- See section below

Diagnosing and Treating Acute Coronary Syndromes

Comprises Unstable Angina/Non-ST Elevation MI (UA/NSTEMI) and ST Elevation MI (STEMI).

1) Bottom Line: If you’re unsure, and the story is good, and it’s safe to anticoagulate, just heparinize and think about it later.

2) As in most medical situations, the patient’s story usually means the most (see the TIMI criteria in #10 below).

3) Review the EKG yourself, and make the differentiation between NSTEMI and STEMI

(ST changes in atleast 2 contiguous leads; 1 mm in limb leads or 2 mm in precordial leads;

diff criteria w/ LBBB –> 1mm STE concordant with QRS, 5mm STE discordant with QRS, or 1mm STD in V1-3)

-> If STEMI, give ASA, start a heparin drip (bolus 80 mg/kg, rate 15 mg/kg/hr) & make sure the cards fellow is aware -> this is a cath EMERGENCY (given better outcomes with initial percutaneous intervention vs thrombolysis).

-> If UA/NSTEMI, you’ll need to think further about demand-side vs supply-side ischemia, need for heparin or other anticoagulation (ie Plavix, GP IIb/IIIa inhibitors), etc.

4) Give everyone Aspirin (4 chewable baby ASA), beta-blockade (if HR/BP will tolerate), SL NTG for anginal pain, nasal canula oxygen, morphine as needed for pain. For recaltrant chest pain with SL NTG, can also consider a Nitroglycerin drip (Tridil) for CP relief (but watch out for hypotension and also for nitro toxicity). Also consider addition of heparin/other anticoag if appropriate or with continued CP.

5) Anticoagulation in ACS: Make sure you perform the stool guaiac before starting anticoagulants. There are multiple studies on the benefit of Low Molecular Weight Heparin (Enoxaparin, 1 mg/kg SQ BID) over Unfractionated Heparin (UFH, bolus 80 mg/kg then drip 15 mg/kr/hr with goal aPTT 60-80), but don’t use Enoxaparin in patients with renal failure (use on obese patients is actually shown to be okay, still dosed by weight, but this hasn’t become commonplace yet so check with your team). Consider Plavix given mortality benefits (CURE trial), but this is a problem if you find 3 vessel disease on cath that requires a CABG because surgery won’t take the pt for 5 days after Plavix dose. Consider addition of a GPIIb/IIIa inhibitor in pts with TIMI score of 4 or greater, or in pts with continued CP even with heparin.

6) Need a cardiac monitor if admitting for r/o MI, NO EXCEPTIONS.

7) Serial cardiac enzymes (CK/MB/Ti, every 8 hours) and EKGs.

8) Keep NPO in case they’ll go to cath, or even if you’re just going to stress them in the AM

9) Bedrest

10) Always nice to calculate a TIMI score to help ascertain risk of ACS/direct acute mgmt/predict future events each grouping gets 1 point:

· CAD: known coronary stenoses > 50%

· Age >= 65

· Risk factors: >= 3 (current smoker, FHx, HTN, Hypercholesterolemia, DM)

· Deviation of ST segments >0.5 mm

· Increased cardiac markers

· Aspirin use in last 7d

· Continued pain: >= 2 anginal episodes in last 24h

Post-Cardiac Catheterization

PEx: - Make sure you feel good fem and distal pulses, LE’s are well perfused

- r/o any groin hematomas and r/o bruits (suspicious for aneurysm) -> if worried, get an U/S

Rx: - if intervention has been made, integrillin x 18hr post prcedure, plavix 75 mg po qd

(don’t forget this at time of discharge!)

If pt is hypotensive post-cath: - must r/o ACS (EKG/Enz), coronary dissection/tamponade (TTE), retroperitoneal bleed or other site of blood loss given anticoagulation (PEx, CT abdo/pelv,H8, guaiac), simply volume down in stg of being NPO for cath

The New Cardiomyopathy (CM) Patient

Types:

• Restrictive (Amyloid, Hemochromatosis, Wilson’s Disease, Sarcoid, etc)

· Dilated (Coxsackie B, EtOH, Cocaine, Ischemic, Doxorubicin, Beriberi, HIV, Thyroid Disease, etc)

· Hypertrophic - IHSS, now called HOCM (genetic, etc)

Diagnostic Cheech:

• History, Transthoracic echo, cardiac cath to r/o vascular disease, HIV, ANA, Thyroid panel, ferritin, urine metanephrines, ceruloplasmin and urine copper, fat pad bx, endomyocardial bx

Congestive Heart Failure (Mgmt of acute exacerbations and long-term disease)

(some relevant studies in parenthesis & italics)

Etiology:

• h/o ischemic heart disease, hypertension, valvular disease, other causes of CM as above
• systolic vs diastolic dysfunction vs both (always try to look up an old echo or cath)
• Exacerbation secondary to recent dietary indiscretions or medication noncompliance, ischemia, infection, medication toxicity, arrhythmias

PEx/Dx:

• PEx is HUGE -> try to assess volume status by assessing JVP, pulmonary congestion, LE edema, sacral edema, etc
• Might hear an S3 or S4 gallop
• Consider getting a pro-BNP (can use this to assess response to treatment as well)

Rx:

• Diuresis with Lasix (IV Lasix is 2x as strong as PO) -> if a pt with poor systolic function comes in with heart failure and is very volume up, may actually need to diurese even if they’re hypotensive (recall the Starling curve) (this is often the case in the cardiomyopathy service patients; get comfortable with the idea of diuresis to address hypotension in these patients)
• If Lasix is not strong enough (double your dosage with each dose up to 240 mg), consider diuril 30 min before lasix, or may eventually need to move on to natriuretic peptide (Natrecor) (but this needs approval from cardiology)
• Afterload reduction with Ace Inhibitors (can start with Captopril TID and uptitrate), also good long-term (CONSENSUS)
• Digoxin is helpful for symptomatic HF, but has no improvement in morbidity/mortality (DIG)
• Salt/Fluid restriction
• Follow weights and I/O’s
• Long-term improved morb/mort with Beta Blockade (MERIT),but avoid in acute exacerbations for neg inotropy reasons
• Improved morbidity/mortality also seen with Nitrates/Hydralazine (v-HEFT-1) and with Aldactone (RALES)
• Try to discontinue calcium channel blockers if possible in pts with systolic dysfunction
• With diastolic dysfunction, calcium channel blockade and beta blockade are helpful to increase filling time and decrease the left ventricular muscle mass

Atrial Fibrillation with Rapid Ventricular Response (Afib/RVR)

Etiology:

• Pulmonary Dz, Ischemia, Ethanol, Mitral Valve Disease, Large Atria, Anemia, Hyperthyroidism, Sepsis, Dilated CM

Dx/PEx:

• Irreg irreg pulse
• Can have hypotension, palpitations, chest pain, dizziness, etc
• Evaluate etiologies as noted above

Rx:

• This pt must be on a monitor
• Start with:

Metoprolol IV 5 mg + PO 50 mg BID

or Diltiazem IV Push 10 mg or 20 mg (over 2 min) + PO 30 mg QID

• If ctrl is difficult to maintain:

Diltiazem drip 5 mg/hr - 15 mg/hr, titrate to HR < 100 bp

• If hypotensive or very bad systolic dysfunction (ie: you don’t want to use B-blockade or CCB’s):

Amiodarone IV 150 mg over 10 min,

then IV 1mg/min for 60 hrs, then 0.5 mg/min for 18 hrs

(but don’t ignore the fact that Amiodarone is not a benign medication)

• Consider anticoagulation (heparin or enoxaparin) if new onset and expecting cardioversion
• Studies show equivalence between rhythm ctrl vs rate ctrl/anticoagulation (AFFIRM, RACE) in pts with asymptomatic AFib, so this becomes a pt-specific decision. If cardioversion is the goal, must be in AFib for <48 hrs or anticoagulated for 6 weeks before the procedure

Pacer / AICD

(A/V/D) chambers paced

(A/V/D/O) chambers sensed

(I/T/D/O) response based on sensing: I: inhibited, T: triggered, O: no response)

(R) rate responsive to physiologic variables

(O/P/S/D) antitachycardia mode: O: none, P: pacing, S; shock)

Shock

Types:

· Septic -> CO / ¯SVR

· Cardiogenic (MI, large PE, etc) à ¯CO / SVR

· Hypovolemic (dehydrated, etc) -> CO / SVR

· Neurogenic (behaves like septic shock) -> CO / ¯SVR

Rx:

· Start immediately with IVF (aggressively), and add pressors as appropriate

· Pressors as appropriate for the situation (see chart below)

Pressor HR inotropy SVR Dose

Dobutamine ++ +++ - 1-20 mcg/kg/min

Dopamine “Renal dose” 0 0 - 1-2 mcg/kg/min

Intermediate 0 + 0 2-10 mcg/kg/min

High dose 0 + + 10 –20 mcg/kg/min

Epinephrine +++ +++ ++ 1-20 mcg/min

Norepinephrine (Levo) ++ ++ +++ 0.5-30 mcg/min

Phenylephrine (Neo) 0 0 +++ 10-200 mcg/min

Vasopressin ++ 0.2-0.4 units/min

Notes: Phenylephrine is often chosen in septic shock, and a good choice for people who are already tachy (no β1 effects).

Vasopressin is the only pressor effective at low pH (often can see a little boost in your pressors if you give some HCO3-).

Dopamine can often be used on monitored floors, not just ICUs.

Hypertension and Hypertensive Urgency/Emergency

Emergency implies evidence of end organ damage (cardiac damage, stroke, renal damage, etc)

Etiology/Dx:

• Idiopathic or “Essential” hypertension is the cause of hypertension in 95 % of patients
• Also consider other causes of hypertension (ie RAS -> check MRA; Pheochromocytoma -> check urine metanephrines/VMA; Hyperaldosteronism -> check aldo & also could be hypokalemic; Cushing’s -> check a dexa suppression test; etc.)
• Exacerbations in our patient population are often the result of medical noncompliance or dietary indiscretions
• Can also present as a result of missed hemodialysis or inadequate dialysis (ie volume issues)
• Evaluate for hypertensive emergency -> cardiac enzymes, pulmonary edema, u/a for RBCs (some say just incr creat is enough to signal a hypertensive emergency), head CT if mental status/neurologic changes, etc

Rx:

• Requires a cardiac monitor
• Can often start by giving pts their prescribed PO medications if they’ve been noncompliant
• Can move on to IV push medications:

Labetalol 20mg IV push

[can try 40mg – 80mg IVP if necessary (q10 min, up to 300 mg)]

or Metoprolol IV 5mg (q5 min, up to 15mg)

• If IV pushes are inadequate, or if hypertensive emergency, use an IV drip:

Labetalol 2mg – 6mg per minute (watch out for bradycardia)

or Nicardipine 5mg – 15 mg per hr (watch out for bradycardia)

or Nitroprusside 0.3 – 10.0 mcg/kg/min

(watch out in renal failure pts for thiocyanate toxicity)

• The ED often uses Nitroglycerin drip (Tridil) for BP control, but it’s really not a great BP med (better for anginal CP)
• Transition to PO meds when ctrl’d with IV
• If hypertensive urgency, bring BP down over hours
• If hypertensive emergency, decrease MAP by 25% in minutes
• Do not bring the BP down too quickly as you risk losing cerebral perfusion, unless the pt has a stroke, then goal SBP 160’s/MAPs 80’s

Syncope

Etiology:

• 1^st make sure it is syncope (ie not that they just fell and ortho is trying to turf a hip fx to medicine) vs dizziness, vertigo, or presyncope
• Can be cardiac vs non-cardiac (ie neuro/other)

Cardiac:

Arrhythmia

(atrial or ventricular)

Valve Disease

(esp aortic stenosis)

ACS

Systolic Dysfunction

HOCM

Tamponade

Aortic Dissection

Pulmonary Embolus

(then Rt sided failure)

Pulmonary HTN

(then cor pulmonale)

Etc.

Non-cardiac:

Carotid Disease

TIA/Stroke

Thromboembolic (from carotids, or paroxysmal emboli from extremities)

Migraines

Seizures

Space Occupying Lesions in the brain

Vaso-Vagal

Hypovolemia

Hypoglycemia

Micturition syncope

(more common in men)

Preceding Coughing Spasm or Bowel

Mvmt (vagal)

Medication Effects

(ie alpha-blockers, etc)

Adrenal Insufficiency

Idiopathic

Etc.

Hx/PEx/Studies:

• Assess volume status (orthostatics, skin turgor, oropharynx, etc) (also consider HF exacerbation or Rt sided failure as a result of large PE by gleaning the hx and by elevated JVP on exam)
• Ask questions to assess if ictal or post-ictal state was present (aura, witnessed seizing, incontinence, confusion, staring)
• Check FS glucose
• Assess heart rhythm on a monitor and ask about palpitations
• EKG/Enzymes for ACS
• Listen for valvular murmurs (as well as carotid and periph pulses, ie pulsus parvus et tardus with AS) and bruits
• For imaging, start out with a non-contrast head CT to r/o any acute intracranial anomaly
• Consider TTE to evaluate mural thrombus and valve/systolic function (and with bubble study to evaluate PFO), LE dopplers to assess DVT, carotid dopplers, head MRI/MRA, and EEG as appropriate given Hx/PEx/Etc.
• Consider checking a cortisol for adrenal insufficiency
• Consider Tilt-table testing for hypervagotonia

Rx:

• Treat the underlying condition as found by workup above

Brugada Criteria to Distinguish SVT from VT

Follow algorithm sequentially.

If ‘yes’ to any criteria = VT. If all 4 criteria absent then dx is SVT with aberrancy (sensitivity 97%, specificity 99%)

Criteria sensitivity for VT specificity for VT

Absence of RS in ALL precordial leads 21% 100%

R (start) to S (nadir) > 100ms in any precordial lead 66% 98%

A-V dissociation 82% 98%

Morphological criteria for VT in V1-2 & V6 (no BBB) 99% 97%

Morphological criteria for VT:

Primarily positive in V1 & in V1 & V6

(monophasic R in V1 or QR or RS in V1 AND R to S <1 in V6 or QS or QR in V6 or monophasic R in V6)

Primarily negative in V1 & in V1 or V2 & V6

(R > 30msec in V1 or V2 or >60 msec to nadir of S wave in V1 or V2 or notched S wave in V1 or V2 AND QR or QS in V6) (Circulation (1991) 83:1649–590)

Treatment: presence of structural heart disease or abnormal EKG predict higher 1 yr mortality & require further evaluation & management of underlying pathology. Neurally mediated syncope: atenolol in limited cases.

[NEJM (2000) 343: 1856 – 62, Circulation (2002) 106: 1606 – 09.]