1
Q
NONpacemaker cell
A
CONTRACTILE CELLS
2
Q
NONPACEMAKER CELL (CONTRACTILE CELLS)
NONPACEMAKER CELL (CONTRACTILE CELLS) is divided into how many phases
A
5
0, 1, 2, 3, 4
3
Q
NONPACEMAKER CELL (CONTRACTILE CELLS)
- RESTING phase
- RESTING membrane potential
- cardiac cells REMAIN until stimulated
- associated with diastole portion of heart cycle
A
PHASE 4
4
Q
NONPACEMAKER CELL (CONTRACTILE CELLS)
- UPSTROKE + FAST DEPOLARIZATION
- OPENING of fast Na channels and rapid depolarization
- drives Na+ INTO cell (inward current), changing membrane potential
A
PHASE 0
5
Q
NONPACEMAKER CELL (CONTRACTILE CELLS)
- SPIKE + A LITTLE BIT REPOLARIZATION
- CLOSURE of the fast Na channels
- K+ channels will OPEN
A
PHASE 1
6
Q
NONPACEMAKER CELL (CONTRACTILE CELLS)
____ and ____ together correspond to the R and S waves of the ECG
A
PHASE 0 and PHASE 1
7
Q
NONPACEMAKER CELL (CONTRACTILE CELLS)
- PLATEAU
- sustained by the balance between the inward movement of Ca+ and outward movmeent of K+
- has a LONG DURATION compared to other nerve and muslce tissue
- corresponds to ST segment of the ECG
A
PHASE 2
8
Q
NONPACEMAKER CELL (CONTRACTILE CELLS)
- DOWN SLOPE + FAST REPOLARIZATION
- K+ channels REMAIN OPEN
- allows K+ to build up outside the cell, causing the cell to repolarize
- corresponds to T wave on the ECG
A
PHASE 3
9
Q
how many phases are there in CONDUCTING cells (PACEMAKER)
A
3 phases only
phase 0, 3, 4
10
Q
- time where action potential CANNOT happen
- REST of the heart
A
REFRACTORY PERIOD
11
Q
this has NO REST because it is the one that creates the signal
A
SINOATRIAL NODE
12
Q
this has RESTING phase because it waits for the signal from the SA node
A
CONTRACTILE MYOCADIUM
13
Q
CONTRACTILE CELLS
A
AV node
Bundle of His
Purkenje fibers
14
Q
CONDUCTING cells
A
SA node
15
Q
ECG WAVE SEGMENTS
CONTRACTION of atria
A
P
16
Q
ECG WAVE SEGMENTS
CONTRACTION of ventricles
A
QRS
17
Q
ECG WAVE SEGMENTS
REPOLARIZATION of ventricles
A
T
18
Q
ECG WAVE SEGMENTS
- represents the time the IMPULSE TAKES to reach the ventricles from the sinus node
A
PR INTERVAL
19
Q
ECG WAVE SEGMENTS
- represents the DURATION of the conduction from the AV node down to the Purkinje fibers
A
PR SEGMENT
20
Q
ECG WAVE SEGMENTS
- represents the duration of VENTRICULAR DEPOLARIZATION
A
QRS COMPLEX
21
Q
ECG WAVE SEGMENTS
- DURATION of VENTRICULAR DEPOLARIZATION and REPOLARIZATION
A
QT INTERVAL
22
Q
ECG WAVE SEGMENTS
- ISOELECTRIC (atrial diastole and ventricular systole)
A
ST SEGMENT
23
Q
REASONS for ARRYTHMIA
A
Abnormal Automaticity
Triggered activity
Re-entry
24
Q
- a heart condition that result in rate and/or timing of contraction of heart muscle that is INSUFFICIENT to maintain normal CARDIAC OUTPUT
A
ARRYTHMIA
25
CAUSES OF ARRYTHMIA
exposure to TOXIC substances
26
# **MECHANISMS OF ARRYTHMIA**
TOO **SLOW**
BRADYCARDIA
<60
27
# **MECHANISMS OF ARRYTHMIA**
TOO **FAST**
TACHYCARDIA >100
28
# **DISORDERS OF IMPULSE FORMATION**
NO SIGNAL from the **pacemaker site**
BRADYARRYTHMIAS
29
# **DISORDERS OF IMPULSE FORMATION**
* may arise from **emergence** of **LATENT PACEMAKERS** -- will result to **premature heartbeat**
* **Abnormal acceleration** of the latent pacemaker rate
development of an ECTOPIC PACEMAKER
| abnormal position
30
# **DISORDERS OF IMPULSE FORMATION**
**SPONTANEOUS depolarization** (especially for **nonpacemaker cells**)
AUTOMATICITY
31
* is the ability of certain cells of the heart (**nonpacemakers**) to undergo **SPONTANEOUS DEPOLARIZATION**, in which an a**ction potential is generated** WITHOUT any **influence** from nearby cells
AUTOMATICITY
32
# **AUTOMATICITY**
INCREASE in the slope of **phase 4**
ENHANCED AUTOMATICITY
33
# **AUTOMATICITY**
**SECOND depolarization** occurs **PREMATURELY**
TRIGGERED AUTOMATICITY
34
# **AFTERDEPOLARIZATIONS**
* occur during **LATE PHASE 2 or PHASE 3**
EARLY AFTERDEPOLARIZATION
35
# **AFTERDEPOLARIZATIONS**
* occur in **LATE phase 3 or EARLY phase 4**
DELAYED AFTERDEPOLARIZATION
36
* has problem with **re-entry**
* there is an **accessory pathway**
WOLF-PARKINSON-WHITE SYNDROME
37
# **TYPES OF ARRYTHMIA**
ARISING FROM **SINUS NODE**:
* **100-150 bpm**
sinus TACHYcardia
38
# **TYPES OF ARRYTHMIA**
ARISING FROM **SINUS NODE**:
* **LESS THAN 60 bpm**
sinus BRADYcardia
39
# **TYPES OF ARRYTHMIA**
**ATRIAL** ARRYTHMIA:
* **around 350 bpm**
atrial FIBRILLATION
40
# **TYPES OF ARRYTHMIA**
**ATRIAL** ARRYTHMIA:
* **250-350 bpm**
atrila FLUTTER
41
# **TYPES OF ARRYTHMIA**
**NODAL** AND OTHER **SV** ARRYTHMIAS
ATRIOVENTRICULAR BLOCK (prolongation of PR interval)
42
# **OBJECTIVES OF ANTIARRHYTHMICS**
RESTORE the ____ to **normal**
cardaic rhythm
43
# **OBJECTIVES OF ANTIARRHYTHMICS**
PREVENT arrythmia ____
occurence
44
# **OBJECTIVES OF ANTIARRHYTHMICS**
AMELIORATE the ____ of the arrythmia
hemodynamic consequences
45
# **OBJECTIVES OF ANTIARRHYTHMICS**
REDUCE the **risk** of a **more severe** arrythmia such as ____
ventricular fibrillation
46
# **GOALS OF ANTIARRYTHMICS**
* DECREASE the **frequency** of **discharge**
* an effect that is MORE PRONOUNCED in **cells with ECTOPIC PACEMAKER** activity than in normal cells
SUPPRESS AUTOMATICITY
47
# **GOALS OF ANTIARRYTHMICS**
* INCREASE the **refractory period**
PREVENT RE-ENTRY
48
# **MAJOR MECHANISMS**
____ blockade
sodium channel
calcium channel
49
# **GOALS OF ANTIARRYTHMICS**
BLOCKADE of ____ in the heart
sympathetic autonomic effects
50
# **GOALS OF ANTIARRYTHMICS**
PROLONGATION of the effective ____
refractory period
51
# **CLASSES OF ANTIARRYTHMICS**
**SODIUM** channel blockers
CLASS I
52
# **CLASSES OF ANTIARRYTHMICS**
Na CHANNEL BLOCKERS:
* CLASS **Ia**
Disopyramide
Quinidine
Procainamide
| Double Quarter Pounder
53
# **CLASSES OF ANTIARRYTHMICS**
Na CHANNEL BLOCKERS:
* CLASS **Ib**
Lidocaine
Tocainide
Mexiletine
Phenytoin
| Lettuce
Tomato
Mayonnaise
Pickles
54
# **CLASSES OF ANTIARRYTHMICS**
Na CHANNEL BLOCKERS:
* CLASS **Ic**
Moricizine
Flecainide
Propafenone
Encainide
| MORe Fries PleasE
55
# **CLASSES OF ANTIARRYTHMICS**
BETA BLOCKERS
CLASS II
56
# **CLASSES OF ANTIARRYTHMICS**
CLASS II BETA BLOCKERS
Propranolol
Atenolol
57
# **CLASSES OF ANTIARRYTHMICS**
K+ CHANNEL BLOCKERS
CLASS III
58
# **CLASSES OF ANTIARRYTHMICS**
CLASS III - K+ CHANNEL BLOCKERS
Bretylium
Sotalol
Amiodarone
Ibutilide
Dofetilide
| BSAID
59
# **CLASSES OF ANTIARRYTHMICS**
the ONLY **beta blocker** that is found in CLASS **III**
SOTALOL
60
# **CLASSES OF ANTIARRYTHMICS**
CALCIUM CHANNEL BLOCKERS
CLASS IV
61
# **CLASSES OF ANTIARRYTHMICS**
CLASS IV - CALCIUM CHANNEL BLOCKERS
Verapamil
62
# **CLASSES OF ANTIARRYTHMICS**
MISCELLANEOUS
| sometimes referred to as class V
Adenosine
Digitalis
63
# **CLASSES OF ANTIARRYTHMICS**
* BLOCK the **fast INWARD SODIUM current**
* sometimes termed as **PVC killers**
* useful for ABOLISHING **premature ventricular contractions (PVC)**
* **Depress Phase 0**
CLASS I
FAST SODIUM CHANNEL BLOCKERS
64
# **CLASSES OF ANTIARRYTHMICS**
CLASS I: FAST SODIUM CHANNEL BLOCKERS are sometimes termed as
PVC killers
65
# **CLASSES OF ANTIARRYTHMICS**
* cause **MODERATE** Phase 0 depression
* PROLONG the **ACTION POTENTIAL DURATION**
* INCREASES **EFFECTIVE REFRACTORY PERIOD**
CLASS Ia
66
# **CLASSES OF ANTIARRYTHMICS**
CLASS Ia:
* **1ST ANTIARRYTHMIC USED**
* used for **DIGITALIS-induced arrythmias**
QUINIDINE
67
what drug is used for **digitalis-induced arrythmias**
DIGIBIND
68
drug for **BRADYCARDIA**
Atropine
69
# **CLASSES OF ANTIARRYTHMICS**
TOXIC EFFECTS | **QUINIDINE**
torsades de pointes arrythmia
Cinchonism (Tinnitus, headache, visual distrubances)
70
QUINIDINE is from
Cinchona spp
71
# **CLASSES OF ANTIARRYTHMICS**
* CLASS **Ia** can cause ____, it is the **many forms** of **ventricular tachycardia**
* **syncope**, **cardiac arrest**
POLYMORPHIC VENTRICULAR TACHYCARDIA
72
it is an **uncommon** and **distinctive** form of **Polymorphic Ventricular Tachycardia (PVT)** characterized by a **gradual change** in the **amplitude** and **twisting** of the QRS complexes around the isoelectric line
TORSADES DE POINTES
73
# **CLASSES OF ANTIARRYTHMICS**
CLASS **Ia**:
* LESS **anticholinergic effects** than Quinidine
* drug of **SECOND** or **THIRD choice** for **sustained Ventricular Tachycardia** associated with **Acute Myocardial Infarction**
PROCAINAMIDE
74
# **CLASSES OF ANTIARRYTHMICS**
TOXICITIES | **PROCAINAMIDE**
Lupus erythematosus
Agranulocytosis - **severe form** of AE, **rare**
75
# **CLASSES OF ANTIARRYTHMICS**
CLASS **Ia**:
* ANTICHOLINERGIC effects are **even more marked** than that of quinidine
DISOPYRAMIDE
76
# **CLASSES OF ANTIARRYTHMICS**
* **WEAK** Phase 0 depression
CLASS **Ib**
77
# **CLASSES OF ANTIARRYTHMICS**
CLASS **Ib**:
* BLOCKS **Na+ channels** mostly in the ventricular cells, also good for **digitalis-induced arrhythmias**
* LEAST **cardiotoxic**
* a **LOCAL anesthetic**
* uses **Epinephrine** to increase effect/duration
* can destroy **liver** if systemic
LIDOCAINE
78
# **CLASSES OF ANTIARRYTHMICS**
TOXICITIES | **LIDOCAINE**
paresthesias
79
# **CLASSES OF ANTIARRYTHMICS**
LIDOCAINE uses ____ to increase effect/duration
EPINEPHRINE
80
# **CLASSES OF ANTIARRYTHMICS**
CLASS **Ib**:
* **ORAL LIDOCAINE derivative**
MEXILETINE
81
# **CLASSES OF ANTIARRYTHMICS**
CLASS **Ib**:
* **ANTICONVULSANT**
* CONTRAINDICATED in **pregnancy** = can cause **Fetal Hydantoin Syndrome**
PHENYTOIN (Dilantin)
82
# **CLASSES OF ANTIARRYTHMICS**
* **STRONG** Phase 0 depression
CLASS **Ic**
83
# **CLASSES OF ANTIARRYTHMICS**
CLASS **Ic**:
* may cause **SEVERE EXACERBATION** of arrhythmia even when b**normal doses** are administered in patients with **PREEXISTING ventricular tachyarrhythmias**
FLECAINIDE
84
# **CLASSES OF ANTIARRYTHMICS**
CLASS **Ic**:
* **WEAK Beta blocker**
* also SOME **Ca channel blockade**
PROPAFENONE
85
# **CLASSES OF ANTIARRYTHMICS**
CLASS **Ic**:
* a **PHENOTHIAZINE** derivative
* has been **withdrawn** from the **US market**
* NOT USED because it has high chance for EPS
* used also for **Bipolar**, **Schizoprenia**
MORICIZINE
86
# **CLASSES OF ANTIARRYTHMICS**
* can stabilize **Na channels**
* BLOCKADE of **myocardial Beta adrenergic receptors**
* DIRECT **membrane-stabilizing effects** related to Na channel blockade
CLASS II - BETA BLOCKERS
87
# **CLASSES OF ANTIARRYTHMICS**
CLASS **II**:
* can be used for **STAGE FRIGHT**
* CONTAINDICATED to **asthma** because it is a **NONselective B-blocker**
PROPRANOLOL
88
# **CLASSES OF ANTIARRYTHMICS**
CLASS **II**:
* **SHORTEST-acting** beta blocker
ESMOLOL
89
# **CLASSES OF ANTIARRYTHMICS**
CLASS **II**:
* **CURRENT SHORTEST-acting** Beta blocker
LANDIOLOL
90
# **CLASSES OF ANTIARRYTHMICS**
* used for patient **NEGATIVELY SENSITIVE** to **Na channel**
* only used when **Class I DOES NOT work**
* cause **delay** in repolarization and **PROLONGED REFRACTORY PERIOD** (blocking of K channel)
CLASS III - K Channel Blockers
91
# **CLASSES OF ANTIARRYTHMICS**
CLASS **III**:
* contains **IODINE**
* can cause **hypo/hyperthyroidism**
* HIGH **efficacy**
* LOW **incidence** of torsade de pointes
* causes **PERIPHERAL VASODILATION** (IV)
AMIODARONE
92
# **CLASSES OF ANTIARRYTHMICS**
CLASS **III**:
* common target of the SE of **Amiodarone**
thyroid hormone
lungs - rare target
93
# **CLASSES OF ANTIARRYTHMICS**
CLASS **III**:
* TOXICITIES | **AMIODARONE**
Fatal pulmonary fibrosis
Optic neuritis (Retrobulbar optic neuritis)
Hypo/Hyperthyroidism
94
# **CLASSES OF ANTIARRYTHMICS**
CLASS **III**:
* **SAFER** than Amiodarone
* NO **thyroid** or **pulmonary toxicity**
DRONEDARONE
95
# **CLASSES OF ANTIARRYTHMICS**
CLASS **III**:
* a **NEW drug**
* an **INVESTIGATIONAL multi-channel blocker** that was developed for the tx of **atrial fibrillation**
VERNAKALANT
96
# **CLASSES OF ANTIARRYTHMICS**
CLASS **III**:
* **FIRST DEVELOPED** to **treat hypertension** but found also to **suppress ventricular fibrillation** associated with **myocardial infarction**
BRETYLIUM
| a hypertensive agent that was found out to be effective in arrhythmia
97
# **CLASSES OF ANTIARRYTHMICS**
CLASS **IV**:
* NONDHP; cardioselective
Verapamil
Diltiazem
98
# **ADENOSINE EFFECT**
in **cardiac tissue**, ADENOSINE binds to ____
type 1 (A1)
99
# **ADENOSINE EFFECT**
**type 1 (A1)** is couplede to ____ leading **decrease cAMP**, causing INHIBITION of **L-type Calcium channel**
Gi proteins
100
# **ADENOSINE EFFECT**
DECREASE **cAMP** causes
inhibition of L-type Ca channel
101
# **ADENOSINE EFFECT**
negative **chronotropy**
inhibits the pacemaker current
102
# **ADENOSINE EFFECT**
negative **dromotropic** effect
decreases conduction velocity
103
# **ADENOSINE EFFECT**
on presynaptic ____ receptors located on **sympathetic nerve terminals**, ADENOSINE **inhibits** the **RELEASE OF NE**
PURINERGIC receptors
| extracellular messengers
104
105
DOC for **PAROXYSMAL SUPRAVENTRICULAR TACHYCARDIA**
ADENOSINE
106
adenosine receptor blockers
theophylline
caffeine
107
* enemies with **Calcium**
MAGNESIUM
108
tx for **ECLAMPSIA** in pregnant women
MgSO4
Epsom Salt
109
# **NON PHARMACOLOGIC THERAPY**
* the **HEAT** (RF ablation) or **FREEZING COLD** (cryoablation) DESTROY the **heart tissue** causing the **fibrillation**
RADIOFREQUENCY CATHETER ABLATION
CRYOABLATION
110
uses **generator**
RADIOFREQUENCY CATHETER ABLATION
111
# **NON PHARMACOLOGIC THERAPY**
* AUTOMATICALLY **detects** and **treats** potentially **fatal arrhythmias**
IMPLANTABLE CARDIOVERTER DEFIB
PCOL 2 Lec
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