Cardiology (SA) Flashcards
1
Q
What is #1?
A
SAN
2
Q
What is #2?
A
AVN
3
Q
What is #3?
A
Bundle of His (AV bundle)
4
Q
What is #4?
A
Left Limb
5
Q
What is #5?
A
Right Limb
6
Q
What is #6?
A
Septomarginal Band
7
Q
What is #7?
A
Left Bundle Branch
8
Q
What is #8?
A
Right Bundle Branch
9
Q
Label 1-9.
A
- Cranial VC
- Caudal VC
- Aorta
- Right Auricle
- Right Atrium
- Pulmonary Artery
- Right Ventricle
- Left Auricle
- Left Ventricle
10
Q
Label 1-9.
A
- Cranial Vena Cava
- Caudal Vena Cava
- Aortic Arch
- Right Atrium
- Pulmonary Artery
- Left Atrium
- Left Ventricle
- Left Auricle
11
Q
Label 1-7
A
- Right Cranial Lobe
- Right Middle Lobe
- Right Caudal Lobe
- Accessory Lobe
- Left Caudal Lobe
- Caudal portion of Left Cranial Lobe
- Cranial Portion of Left Cranial Lobe
12
Q
Label 1-4. (Right Lung Lobes as L Lateral)
A
- Cranial Lobe
- Caudal Lobe
- Middle Lobe
- Accessory Lobe (need orthogonal views)
13
Q
Label 1-3
A
- Cranial Portion of Left Cranial Lobe
- Caudal Portion of Left Cranial Lobe
- Left Caudal Lobe
14
Q
Describe Starlings Law.
A
Hydrostatic pressure across the vessel wall and oncotic (protein) pressure within and outside the vessel balance to determine movement of fluid.
15
Q
What is the Equation for Starlings Law?
A
Net pressure = (Pcapillary– Pinterstitium) – (Ocapillary– Ointerstitium)
P = Hydrostatic Pressure, O = Oncotic Pressure
16
Q
What occurs if the result of a starlings equation is positive?
What about if it is negative?
A
+ = water moves out of capillary
- = water moves into capillary
17
Q
What is the equation for Cardiac Output?
A
CO = SV x HR
18
Q
What is the equation for stroke volume?
A
EDVV - ESVV = SV
19
Q
What causes an increased preload?
A
Increased EDVV
20
Q
What causes an increased afterload?
A
Increased vascular presure
21
Q
What is vascular resistance inversely proportional to?
What is the significance of this?
A
Radius4
Increased Radius = Decreased Vascular Resistance & vice-versa.
22
Q
How is mean Aortic Pressure Calculated?
A
Total Peripheral Resistance x CO
23
Q
What is the systolic pressure of the RV?
A
25mmHg
24
Q
What is the systolic pressure of the LV?
A
120mmHg
25
What is the normal systolic pressure of the pulmonary arteries?
25mmHg
26
What is the normal systolic pressure of the systemic arteries?
120mmHg
27
How can we increase Cardiac Output?
Increase SV (Contractility or EDVV)
Increase HR
28
Sympathetic Drive increases HR but maintains CO - how?
Offsets severely reduced diastole with increase in:
Contractility
Lusitropy
(can also shorten systole to slightly inc diastole)
29
What is the adult remnant of the umbilical vein?
The round ligament of the liver
30
What is the adult remnant of the umbilical artery?
The round ligament of the bladder
31
Which 3 breeds of dog are predisposed to aortic stenosis?
Boxer
Newfoundland
Rottweiler
32
What structural change(s) may be caused by Aortic Stenosis?
LV dilation/hypertrophy
33
What are the clinical signs of Aortic stenosis?
Normally Asymptomatic - occasionally syncope.
Possibly also arrhythmia and sudden death.
34
Which dog breeds are commonly predisposed to pulmonic stenosis?
Bulldogs and Fox Terriers
35
What structural CV changes are caused by pulmonic stenosis?
dilation +/- hypertrophy of the RV
36
What are the clinical signs of pulmonic stenosis?
RHS heart failure
37
Which species most commonly suffers from PDA?
Dogs
38
Where does the blood travel in a PDA?
Aorta to Pulmonary Artery (L --\> R)
39
What are the clinical signs of PDA?
LHS CHF - Pulmonary Oedema
Pulmoanry hypertension & shift to R \> L flow = Differential Cyanosis (blue caudal MMs)
40
Desribe a PDA murmur.
Systolic + Diastolic
Rib Space 3/4
"Machinery Murmur"
41
Describe the murmur caused by Aortic Stenosis.
Sytolic.
4th ICS.
High-Pitched.
42
Describe the murmur caused by Pulmonic Stenosis.
Systolic
3rd ICS
43
Describe the murmur caused by a Small VSD.
Systolic
RHS - ICS 5
Loud, High-pitched.
44
Describe the murmur caused by a large VSD
Systolic
ICS 5 RHS.
Low, soft murmur.
45
Which 4 conditions encompass the Tetralogy of Fallot?
VSD
Dextraposed Aorta
Pulmonary Stenosis
RV Hypertrophy
46
Which cardiac defect may cause megaoesophagus?
Persistent right 4th Aortic Arch & L ductus arteriosus.
47
Which Cardiac Glycoside is used in Veterinary Medicine?
Digoxin
48
How do Cardiac Glycosides work?
Inhibit Na removal from cardiac myocytes.
Increases intracellular Ca & therefore SR Ca.
+ Inotrope
ALSO -ve Chronotrope via inhibition of Na Removal
49
Which receptors are present on cardiac myocytes?
ß1
50
Which ß1 agonist do we use in anaesthesia and why?
Dobutamine - to induce tachycardia.
51
What is the role of phosphodiesterase?
Degardes intracellular cAMP
52
What do PDE III inhibtors do to the heart? How?
Increase contractility.
Increased cAMP --\> inc Ca channel opening --\> increase Ca in myocyte.
53
Apart from increased contractility, what CV effects do PDE inhibitors have on?
Vasodilation
Tachycardia
54
What is the most common PDE III inhibitor used in veterinary practice and what are its major CV effects?
Pimobendan
+ inotrope, vasodilator
55
What are the potential adverse effects of PDE III inhibitors?
Inappetance
Lethargy
Dyspnoea
Azotaemia
56
What is the most appropriate treatment for a Bradyarrhythmia?
Pacemaker implantation
57
What can you use during anaesthesia to combat Bradycardia?
Anticholinergic - Atropine
58
What are the 4 classes of Vaughn-Williams?
I - Na blocker
II - Beta blockers
III - K blocker
IV - Ca blocker
59
How do Class I Vaughn-Williams drugs work?
Block fast Na channels and reduce heart rate.
K+ dependent: hypoK decreases fct, hyperK increases it.
60
Describe the Na blockade and effect on refractory period of VW class Ia drugs.
Na Blockade: Moderate
ERP: Increased
61
Describe the Na blockade and effect on refractory period of VW class Ib drugs.
Na Blockade: Weak
ERP: decreased
62
Describe the Na blockade and effect on refractory period of VW class Ic drugs.
Na Blockade: Strong
ERP = no change
63
Give an example of a VW class 1a drug.
Quinidine
64
Give an example of a VW class Ib drug.
Lidocaine
65
Give an example of a VW class Ic drug.
Flecainide
66
What is the route of administration for quinidine?
Oral
67
What are the 2 effects of quinidine?
Na blocking
Vagolytic (inc HR/conduction)
68
What is quinidine used to treat?
Atrial Fibrillation in horses
69
What are 4 possible side effects of quinidine?
Arrhythmia
GI signs
Behavioural - nervous/depression
Negative inotrope/vasodilation --\> CHF
70
What is the route of administration for lidocaine when treating dysrhythmia?
SLOW IV!
71
On which cells does lidocaine have most effect?
Diseased cells
72
What are the side effects of lidocaine?
CNS excitation
Disorientation/Nausea
Seizures
73
What are the 4 ways beta blockers affect the CVS?
Slow pacemaker potential (slower Ca influx)
Slow AV conduction (inc refractory period)
Negative Inotrope
Reduced lusiotropy
74
Which conditions (2) may we treat with Beta Blockers?
sVT/VT
Hypertension
75
Give an example of a Beta blocker used in practice.
Atenolol (B1 selective)
76
How do K channel blockers slow the HR?
Slows repolarization --\> Increased refractory period
77
Give an example of a VW class III drug.
Sotalol
78
What are the two isomers of Sotalol?
I-Isomer: B1 and B2 blocker
D-Isomer: Blocks K+ Channels
79
How do Ca channel blockers slow the HR?
Slows conduction at SA/AVN
Also negative inotrope and + lusiotrope
80
Give and example of a class IV antidysrhythmic
Diltiazem
81
Give an example of a "Class V Vaughn-Williams" drug.
Digoxin
82
How does digoxin affect the CVS?
Slows AVN conduction (in refractory period) = -ve chronotrope
Vagomimetic.
NO negative inotropy!
83
What are the 6 classes of DIRECT vasodilator?
Nitrates
Dopamine
Ca channel Blockers
PDE III inhibitors
Hydralazine
K+ channel activators
84
How do nitrates cause vasodilation
NO converts GTP to cGMP
cGMP opens K+ and closes Na+ --\> hyperpolarisation
cGMP also inhibits Ca entry to cell --\> relaxation
85
Give an example of a nitrate used in practice & when this would be.
Nitroglycerine - severe acute LHS CHF
86
How is nitroglycerine administered to the patient?
Transdermally - ear/groin/axilla
87
Which type of vessels are dilated by hydralazine?
Ateries - arteriodilator
88
Circulation to which organ systems is most affected by Hydralazine?
Coronary
Cerebral
Renal
Splanchnic
89
How does Hydralazine affect preload/afterload?
BIG drop in afterload
90
What are the 3 major effects of hydralazine of vascular smooth muscle?
Reduced Ca release from SR
Hyperpolarisation of SM
NO release from endothelium
91
What are the overall effects of hydralazine on the CVS?
Vasodilation --\> Reflex tachycardia --\> inc CO
92
What are PDE III inhibitors used for?
CHF
93
Give an example of a PDE V inhibitor.
Sildenafil (viagra)
94
What is the most common use for sildenafil in veterinary practice?
Decrease pulmonary hypertension
95
What are the two pathways INDIRECT vasodilators work on?
Sympathetic
RAAS
96
Which two drugs may be used for a1 adrenoreceptor blockade? Which is non-selective?
Prazosin
Phenoxybenzamine (non-selective)
97
What is a common use of prazosin in veterinary medicine?
Urinary Blockade - relaxes urtheral sphincter
CHF - reduce sympathetic drive
98
How does the RAAS influence preload?
Retrains water and Na+
99
Which conditions would benefit from RAAS blockade?
CHF
Hypertension
CKD
100
How do ACE inhibitors affect the CVS?
Vasodilation & reduced circulating volume:
- improved perfusion
- reduced preload
- reduced arterial pressure
101
Which ACEI should be used in patients with renal compromise?
Benazepril - not renally excreted
102
Name 3 commonly used ace inihibitors in veterinary medicine
Enalapril
Ramipril
Benazepril
103
Which AII receptor antagonist is used in veterinary practice? What is it licenced for?
Telmisartan
Protein-losing nephropathy in cats
104
How do Aldosterone antagonists work?
Reduce Na/H20 retention
Reduce K loss
Reduce Cardiac remodelling
105
Give an example of an aldosterone antagonsit used in veterinary practice
Sprionolactone
106
What are the 4 types of diuretic we can use to reduce preload? Give an example of each.
Loop - furosemide
Thiazide - Hydrochlorothiazide
K sparing - spironolactone
Osmotic - Mannitol
107
A murmur caused by what is heard at the right apex?
VSD
108
Where is a PDA murmur heard?
Dorsal to Aortic Valve
109
Where is the PMI of a mitral valve murmur?
Left Apex
110
Which murmur(s) has/have a PMI at the left base?
Pulmonic & Aortic
111
Which left basillar systolic murmur has a crescendo-decrescendo pattern?
Pulmonic Stenosis
112
Which murmur is often described as a machinery murmur?
PDA
113
Why is s3 heard?
Poor LV compliance ie. DCM
114
Why is s4 heard?
atrial contraction if abrnomal V relaxation ie. HCM
115
When are crackles and wheezing head?
Crackles - inspiratory
Wheeze - expiratory
116
What is class A heart Disease?
At risk - no strutctural abnormality
117
What are class B1 and B2 cardiac Dz?
B: Structural abnormality w/o clinical signs.
1: no remodelling
2: remodelling
118
What is class C 1 and 2 heart disease?
C: structural abnormality w/past or present signs of failure.
C1: CHF, hospitalisation needed
C2: Home Tx of CHF (poss after hospital)
119
what is class D heart Dz?
Persistent/end-stage heart failure signs.
Refractory to standard Tx.
May be acute decompensation for CHF.
120
Define Heart Failure
Clinical Syndrome caused by heart Dz resulting in poor systolic/diastolic function which is too severe for compensation.
Results in poor CO, Oedema and Effusion.
121
What is ANP released in repsonse to?
Atrial stretch
122
What is BNP released in response to?
Increased Ventricular Pressure
123
How to Ace Inhibitors protect the heart from failure?
Counteract ANG II.
Reduce aldosterone release.
Reduce H20/Na retention.
Reduced BP
Reduce Cardiac Remodelling.
124
Why is sipronolactone used in conjunction to ACE inhibitors in CHF?
Aldosterone levels can still increase w/Ace inhibition.
Therefore remodelling still present.
Spironolactone = Aldosterone Antagonist
125
What is the cause of concentric hypertrophy?
Pressure overload
126
What is the cause of eccentric hypertrophy?
Volume Overload
127
Which diuretic is essential for controlling CHF?
Furosemide
128
The dosage of which drug should be adjusted according to RR measured at home by the owners?
Furosemide
129
What are the 2 major side effect of furosemide?
Pre-renal azotaemia
Hypokalaemia
130
If Furosemide does not work for managing CHF at 3mg/kg q8h, what should be done? Any concerns?
MAX DOSE
change to torasemide (0.1mg/kg/day)
MAY CAUSE AKI- check renal fct 48h after each change in dose
131
Which K sparing diuretic is often used in CHF?
Spironolactone
132
What must be done before starting diuretics in a dog with RCHF?
Check for pericardial effusion!
133
Name 4 ACE inhibitors used in veterinary medicine.
Enalapril
Benazepril
Ramipril
Imidapril
134
In what type of heart disease are ace inhibitors contra-indicated?
Fixed outflow tract obstruction with no CHF
135
Which CHF drug can cause venodilation, aiding in rapid control of pulmonary oedema?
Furosemide IV
| (also topical nitroglycerine ointment)
136
Which 3 arteriodilators may be of aid to mitral regurg?
Pimobendan
Amlopdipine
Hydralazine
137
Name 2 balanced vasodilators.
ACE inhibitors
Pimobendan
138
Which drugs sensitises cardiac myocytes to Ca and inhibits PDE?
Pimobendan
139
What is the ideal drug protocol for a Doberman with DCM?
SPAF + Digoxin
140
Which drug can be used to counteract sympathetic drive in heart failure by increasing vagal tone?
Low dose Digoxin
Negative Chronotrope
Partial + inotrope
141
Name 5 signs of digoxin toxicity.
Cardiac arrthymias
Borborygmi
Depression
Anorexia/V+D+
142
If an owner can't afford the SPAF protocol - which 2 drugs must be prioritised?
Furosemide and Pimobendan
143
When does sinus arrhytmia occur in the dog?
HR \<140bpm - NORMAL
144
When does sinus arrhytmia occur in the cat?
ABNORMAL inc vagal tone - asthma or compromised resp
145
What causes a wandering pacemaker? (dog)
Varying vagal tone
146
How can you tell if sinus arrest is vagally mediated?
Abolished by atropine - atropine response test
147
Describe Sick Sinus Syndrome
A few normal beats, Then junctional escape complexes with NO P WAVE!
148
What is the best treatment for sick sinus syndrome?
Pacemaker
149
What causes wide, bizzare QRS complexes?
VPCs
150
How is VTAC treated?
IV lidocaine
151
What is the prognosis for VFIB?
DEATH
152
Describe 1st degree AV block.
1:1 P:QRS
LONG P-R interval
153
What are the 2 types of 2nd degree AV block?
Type I = Variable P-R interval with dropped P wave
Type II = constant P-R interval, fixed P:QRS but not 1:1
154
What is the best treatment for MObitz type II AV block?
Pacemaker implantation
155
What is 3rd degree AV block?
No association of P:QRS complexes
156
What is a negative P wave with an early QRS complex called?
Supraventricular Premature complex
157
How is AFIB controlled?
Slow AVN conduction - Digoxin?
158
How is supraventricular tachycardia controlled?
Vagal manouvres - carotid massage and ocular pressure
Slow AVN conduction
159
What are the 5 causes of a dampened QRS?
Giant Breed
Fat
Thoracic Mass
Pleural Effusion
Pericardial Effusion
160
What is P Mitrale and what does it indicate?
Wide P wave - LA enlargement
161
What is P Pulmonale and what does it indicate?
Tall P wave - RA enlargement
162
What does a tall R wave indicate?
LV enlargement
163
What does a prolonged QRS indiate?
LV enlargement
164
What condition causes tall, wide WRS complexes with opposing T waves?
LBBB
165
What causes deep, wide S waves (neg QRS) with positive T wave? (it would also have R axis deviation)
RBBB
166
What causes + QRS in lead I but -ve QRS in lead, II, III and aVF, with a left axis deviation?
Left anterior fascicular block
167
What may cause Tall/spiky T waves, no P waves, and sinus arrhythmia?
Hyperkalaemia - sinus bradycardia and atrial standstill
168
What are the significant figures for changes in ST segment?
Elevation \>0.15mV
Depression \>0.2mV
169
Which echocardiographic view will evidence MOST cardiac problems?
Right Parasternal Long Axis 4 chamber view
170
What is M Mode used to measure?
Systolic Function
171
What is the normal LA:Ao ratio?
\<1.5
172
Which equation is used to assess the severity of stenosis?
Modified Bernouilli Equation (PG = 4v2)
173
What are the values for mild, moderate and severe aortic/pulmonic stenosis?
0-40mmHg Mild
40-80mmHg Moderate
\>80mmHg Severe
174
175
