Lit Cardiovascular Flashcards
What was the difference between the PetMAP vs HDO devices when measuring systolic BP in dogs?
Lyberg JVIM 2021
Mean SBP with petMAP was 14mm Hg higher vs HDO, and the difference between devices increased with increasing SBP. Underscore the need for validation of BP devices used clinically.
What was the diagnostic utility of a point-of-care NT-proBNP ELISA assay in clinically healthy cats in GP?
Lu JVIM 2021
Overall 43% sens, 96% spec in differentiating abnormal cats –> low sens indicates not effective as screening test, but positive result likely indicates cardiac dz & should FU with echo. Improved sens (71%) while maintaining similar spec (92%) if test is performed on cats with heart murmur.
What was the diagnostic utility of modified-vertebral left atrial size (M-VLAS) in determining left atrial enlargement in dogs with MMVD and comparison to an existing method?
Lam JVIM 2021
M-VLAS = series of measurements based on VHS, VLAS & RLAD (LA dimension). Cut-off value of ≥3.4 vertebrae using M-VLAS had 92.7% sens & 93.1% spec in predicting LA enlargement.
M-VLAS is superior to VHS – offers an accurate and repeatable way to radiographically identify LA enlargement (LA:Ao >/= 1.6) in dogs with MMVD.
a) Define left ventricular-arterial coupling (VAC) and b) its utility in the diagnosis and prognostication of dogs with MMVD.
Osuga JVIM 2021 (2 papers)
a) VAC is derived from estimate Ea (effective arterial elastance) to Ees (LV end-systolic elastance) ratio (Ea/Ees) by echo.
*Ea reflects arterial load of LV, Ees reflects LV systolic function.
b) Ea/Ees ratio was higher in stage C > B2 > B1 MMVD vs healthy dogs. Inappropriate VAC is associated with advanced disease severity in MMVD dogs.
Dogs with Ea/Ees >0.34 had poorer prognosis (50% shorter survival - MST 527d) vs dogs with Ea/Ees ≤0.34 (MST >1112d).
What was the correlation of serum Cl- at admission in dogs & cats with acute heart failure and the following:
a) Diuretic (frusemide) dose
b) Duration of hospitalisation
c) Survival time
Roche-Catholy JVIM 2021
a) Dogs only - neg correlation (worse hypoCl –> higher diuretic doses) may be useful as a marker of disease severity & therapeutic response in CHF dogs.
b) No sig correlation
c) No sig correlation
What were the effects of pimobendan in the outcome of cats with HCM and controlled CHF with/without LVOTO?
Schober JVIM 2021
No sig diff in outcome between treatment groups (pimo vs placebo).
Overall no identified benefit of pimobendan on 180d outcome (w/o needing furosemide dose escalation or death).
NB: Pimo did not induce/worsen LVOTO in HCM cats based on mean systolic PG measurements. PG across LVOT did increase post-pimo but cats were not clinical (weakness, severe hypotension, syncope, death). In fact, cats receiving chronic pimo tx had decreased LVOTO severity –> debunks concerns about long-term detrimental effects of pimo worsening LVOTO.
The prevalence of atrial fibrillation in MMVD dogs was ……%.
Risk factors for AFib development include ….(signalment), ….. stage MMVD. Associated echo parameters included decreased…., increased ….. and presence of ……
Guglielmini JVIM 2021
2.7%, mixed breed, male, advanced, fractional shortening, left atrial & ventricular dimension, pulmonary hypertension.
What was the effect of correcting serum [Cl-] in dogs with Stage C-D CHF?
Adin JVIM 2021
Serum [Cl−] increased after mathematical correction in Stage D CHF dogs but not in Stage C and non-CHF dogs. Although c[Cl−] was higher than m[Cl−] in Stage D dogs supportive of relative water excess, hypochloremia persisted, consistent with concurrent loop diuretic effects on electrolytes.
Serum chloride concentration useful in defining all stages of heart disease in dogs (true/false).
Adin JVIM 2021
True. Serum [Cl-] was the best differentiator of HD stage, a useful marker for stage D dogs.
What were the effects of pimobendan on left atrial function in cats with HCM?
Kochie JVIM 2021
Mild positive effect. Echo parameters – increased peak velocity of left auricular appendage flow, max LA volume, LA total emptying volume, peak velocity of late diastolic transmitral flow (A peak velocity), A velocity time integral.
What were the effects of diet change following a diagnosis of DCM in dogs?
Freid JVIM 2021
Overall improvement in cardiac function – decreased LVIDs & LA:Ao, longer survival (337d vs 215d with no diet change).
Which breed had LV M-mode prediction intervals that deviated from the population of dogs analysed?
Esser JVIM 2021
Newfoundland
*Sighthounds had increased cardiac dimensions (except Irish Wolfhound)
Which echo parameters were useful in predicting the first onset of AFib in dogs with MMVD?
Baron Toaldo JVIM 2021
Standard echo measurements – LA diameter, LVIDd
LA speckle tracing echo (STE) variables – peak atrial longitudinal strain (PALS) (represents the peak strain value during LV contraction)
How did torsemide compare to furosemide as 1st-line PO treatment for dogs with CHF associated with degenerative mitral valve disease, in terms of:
a) Treatment efficacy
b) Clinical response
c) Time to cardiac-related death
Besche JVIM 2020
a) TOR was non-inferior to FURO wrt achieving efficacy criterion by D14 (decreased pulmonary oedema & cough, no worsening of dyspnea or exercise tolerance).
b) Similar clinical response at D84 (74% dogs achieved with either TOR or FURO).
c) TOR significantly decreased risk of cardiac-related death (increased time to death or euthanasia).
What were the cardiovascular effects of oral steroid administration (2mg/kg/d) in healthy cats? (List 2 with significant changes & 1 without)
Block JVIM 2020
- Increased heart size (LA & LVID)
- Increased % change in individual NT-proBNP (>60% increase in 60% cats)
Overall suggests plasma volume expansion.
- No significant changes in BP.
Suspected findings are due to mineralocorticoid induced Na & H2O retention, due to BG remaining stable, as was BP.
What were the 2 major characteristics associated with plasma NT-proBNP concentration in cats?
What were the diagnostic test sensitivities & specificities for the NT-proBNP POC test & ELISA?
Hanås JVIM 2020
Male & HCM cats - higher NT-proBNP concentrations.
ELISA & POCT had similar sens & spec for detecting all 3 groups (HCM, HCM+LAE, HCM-LAE). Spec 97-98% for all groups. Sens - HCM cats 72-74%, HCM+LAE 100%, HCM-LAE 69% (note significant drop in the absence of LAE in HCM cats).
1) What were the main risk factors for development of transient myocardial thickening (TMT) in cats vs persistent HCM?
2) What was the outcome & prognosis of cats with CHF associated with TMT? And in comparison with CHF-HCM cats?
Novo Matos JVIM 2018
1) TMT - younger cats (2yo), antecedent events (recent GA»_space; trauma, +/- drugs or other systemic illness)
2) Maximal LV wall thickness & LA:Ao ratio decreased in 3.3 months.
Overall prognosis better in cats with TMT-CHF cf HCM-CHF. Reduction in LA/Ao over ~3 months.
100% survival in TMT cats, 56% HCM cats. Rare for CHF recurrence (5% TMT vs 71% HCM), most cases (95%) tx discontinued.
a) What characteristics were cats with HCM & outflow tract obstruction (OTO) more likely to have compared to cats without OTO?
b) What was the safety & efficacy of pimobendan in these 2 cat populations?
Ward JVIM 2020
a) OTO cats - younger, more likely cardiac murmur, more likely to manifest CHF as pulmonary oedema, less likely pleural effusion.
b) Overall well tolerated drug, SE in 4.6% cats (5.4% non-OTO cats 2% OTO cats). Most common GIT,lethargy, weakness. Drug stopped in 1.5% cats due to AE.
- Which 4 major echocardiographic variables affecting the right heart were noted in dogs with pulmonary hypertension (PHT)?
- Name 3 R-cardiac echo variables which were negative prognostic factors in relation to survival time in dogs with PHT.
Visser JVIM 2020
- RA enlargement 88%, RV enlargement 69%, PA enlargement 72%, decreased RV function (decr TAPSE) 33% dogs.
- Increased RA area, decreased RV function (TAPSE < 3.23mm/kg0.284) & R heart failure.
1) When comparing diagnostic performance, the VHS+VLAS had better ability to predict echocardiographic L heart enlargement (LHE) in preclinical MMVD dogs compared to VHS and VLAS alone. (T/F)
2) VHS ….. excluded pre-clinical MMVD dogs with LHE (sens…., spec….), while VHS …… (sens…., spec…) identified MMVD dogs with LHE.
Poad JVIM 2020
1) False - no diff, all moderate ability.
2) </=10.8, 91.1%, 69.4%. >11.7, 32.4%, 97.2%
There was a positive association between LA enlargement & cardiomegaly & bronchial narrowing in coughing dogs with cardiac murmurs. (T/F)
Lebastard JVIM 2021
True. Association supports heart size-associated exacerbation of cough in dogs with murmurs.
(2 papers)
The Amplatzer vascular plug II (AVP-II) device was safe & effective for closure of …. PDAs, with a closure rate of …..%, most of which occurred after …….
What is the advantage of using the Amplatzer Vascular Plug 4 to correct L-R PDA in small dogs? Was this effective?
Hildebrandt JVIM 2021
Moderate-large, 100%, 24hrs (1 dog had delayed complete closure after 3mths).
Hulsman JVIM 2020
(2 papers)
AVP-4 is the only self-expandable nitinol mesh occlusion device
which can be implanted through a 4Fr diagnostic catheter, so it is small enough to fit through the femoral artery diameter.
Yes, effective & technically easy. 5/7 dogs had immediate shunt closure, 1 dog with slightly undersized device had delayed closure after 2hrs, 1 dog with severely undersized AVP-4 had device embolised in the PA & required coil placement instead.
In dogs & cats with bidirectional and continuous right-to-left (reverse) PDA, list:
1) Clinical signs (including most common)
2) Prognosis (median survival time, negative or positive prognostic factors)
Greet JVIM 2021
1) Variable CSx:
Dogs - HL collapse most common. Exercise intolerance, signs of neuro disease, signs of GI dz, syncope, cough
Cats - variable.
Both - abdo distension, tachypnea/ dyspnea, asymptomatic.
2) MST 626d in dogs (range 1-3628d).
- Negative px: dogs with R-CHF at presentation (MST 58d vs 1839d).
- Positive px: dogs tx with sildanefil at presentation (MST 1839d vs 302d).
What is native vs contrast T1 mapping? What 2 key determinants cause increased T1 values?
Fries JVIM 2021
T1 mapping measures the longitudinal or spin-lattice relaxation time of tissues. All tissues have inherent T1 relaxation times that are based on a composite of their cellular and interstitial components.
2 impt determinants:
1) Interstitial oedema secondary to infarction with associated cellular destruction
2) Increased interstitial space from fibrosis.
Native T1 values are a composite signal of myocytes & cardiac extracellular volume fraction (ECV), whereas contrast-enhanced T1 mapping can specifically calculate the ECV fraction.
Cardiac extracellular volume fraction (ECV) correlated to variables of ….. in preclinical HCM cats, including …… (incr/decr) E:A, ….. (incr/decr) deceleration time of E wave, and ….. (incr/decr) A wave as compared to healthy cats.
(See CVS chapter flashcards for questions on E:A wave)
Fries JVIM 2021
Diastolic function
Decreased
Increased?
Increased
What is spectral doppler imaging, and differences with colour Doppler echo?
(T/F) Hepatic venous flow is mostly anterograde, with small amount of retrograde flow being normal.
What are the 4 phase patterns of hepatic venous flow in relation to the right atrium/ventricle documented on spectral Doppler flow?
Silva JVIM 2020
Colour Doppler shows the direction of the blood flow in red or blue (either towards or away from the transducer). Meanwhile, spectral Doppler not only shows the direction of blood flow, it also shows the phases (pulsatility) and acceleration of the blood flow. Spectral Doppler imaging is routinely performed for cardiac valves, vascular and other pathological lesions to assess blood flow direction and measure velocity.
True
Hepatic spectral Doppler findings correlates with RV systolic and diastolic indices.
- A wave: retrograde. Represents right atrial contraction
- S wave: largest anterograde wave. Occurs in ventricular systole, as the walls contract and the tricuspid annulus is directed to the apex, generating negative pressure and pushing blood out of the liver.
- V wave: transient; anterograde, retrograde or neutral. Result of atrial filling as systole becomes less intense and the tricuspid valve returns to its normal position.
- D wave: anterograde. Occurs during passive filling of the atrium and right ventricle (RV) during diastole.
a) Which 2 biomarkers were negatively associated with survival in CHF cats with primary cardiomyopathy?
b) Which 3 acute phase proteins (APP) were positively associated with NT-proBNP & left atrial size in CHF cats with primary CM?
c) Name 1 other APP (not included in the answers for the above 2 questions) which was an independent prognostic factor in CHF cats.
Liu JVIM 2020
a) SDMA, NT-proBNP
b) Leucine-rich alpha-2-glycoprotein 1, SAA & ceruminoplasmin
c) a1-acid glycoprotein concentration
Which 2 sites on ultrasound were used to assess aortic stiffness in hypertensive vs normotensive dogs?
What is the clinical utility of aortic strain measurements?
Corda JVIM 2020
2 different Ao transverse sections:
- Caudal to the left renal artery (K_AoSt)
- Cranial to the external iliac arteries (I_AoSt))
K_AoSt and I_AoSt indices can be used to assess systemic hypertension-related Ao stiffness, especially when NIBP measurements are inconsistent or inaccurate.
What are the differences in clinical features of MMVD between Yorkshire Terriers & Mini Schnauzers?
DeProspero JAVMA 2021
Mini Schnauzers:
- Significantly higher MMVD prevalence, much younger at time of diagnosis.
- More likely to have MV prolapse & syncope (potentially 2’ to SSS or airway disease e.g. tracheal collapse)
Yorkies:
- More likely to have coughing
What is a palliative, minimally invasive interventional treatment option for MMVD-associated CHF in dogs?
Overall benefit & outcome in this study population?
Allen JAVMA 2021
Transoesophageal US + echo-guided LA decompression. Involves a minimally invasive creation of an atrial septal defect to significantly & immediately reduce LA pressure.
Successful outcome in 100% (17) dogs w/o intra-op deaths.
MST 195d (0-478d).
When echocardiography is not available, lateral radiographs can be performed to measure ….., where a value >/= ……has high specificity of …… for diagnosis of stage B2 MMVD in dogs. However, false negatives occur in ……% cases using this cut-off.
Stepien JAVMA 2020
Vertebral LA score (VLAS)
≥ 3 vertebral body units (VBUs)
96%
60%
What was the utility of the manubrium heart score (MHS) in differentiating between left and right-sided cardiac disease in dogs?
Mostafa JAVMA 2020
- L-sided cardiac dz: supportive - combo of high short-, long- & overall-MHS.
- R-sided cardiac dz: highest mean CSI. Supportive - high short-MHS WITHOUT high long-MHS & high overall MHSs.
FYI: all dimensions quantified on R lateral TXR.
CSI (cardiac sphericity index) = cSAL:cLAL ratio.
ML: manubrium length (1st bone along sternum).
Short-MHS = cSAL:ML ratio
Long-MHS = cLAL:ML ratio
Overall-MHS = (cLAL + cSAL)/ML
VHS = # of vertebrae (beginning at the cranial end plate of T4) that represented the same length as that of (cLAL + cSAL).
What 2 gene mutations are implicated in Dobermans predisposed to DCM and what were the frequency of these variants identified?
Meurs JAVMA 2020
PDK4 (pyruvate kinase dehydrogenase 4) gene - involved in mitochondrial energy production.
TTN (titin) gene - sarcomeric gene involved in cardiac contraction.
TTN variant most common (58%, 28/48), 20% (10/48) both variants, 12.5% (6/48) neither variant, 8% (4/48) only PDK variant.
What is the effect of a single SQ dose of BNP1-32 on dogs with Stage C MMVD?
Yata JVIM 2019
BNP1-32 = synthetic BNP.
BNP1-32 was well tolerated. Rapidly absorbed after dosing –> led to increased urinary cyclic guanosine monophosphate (UEcGMP) (mediator of diuresis, natriuresis,
vasodilation & RAAS antagonism) 1-2hrs after. But no measurable effects on biological outcomes (UOP, BP, HR, FENa/K, and plasma [aldosterone]) in this study.
What is troponin? What are its 3 subunits & their functions?
What is a drug that acts on any 1 of these troponin subunits?
Langhorn JVIM 2016 (Review)
Cardiac-specific protein. Troponin complex controls cardiomyocyte contraction.
I, C & T subunits. Actin = thin filament, myosin = thick filament.
- T secures tropomyosin to the thin filament (T for thin)
- I inhibits ATP hydrolysis for actin & myosin interaction (I for inhibitory).
- C binds Ca2+ when contraction is initiated. (C for Ca2+ & contraction)
Pimobendan - positive inotrope. Ca-sensitizing effect on the contractile proteins by increasing affinity of the cTnC for Ca2+»_space; promotes increased contractility w/o decreasing free cellular Ca2+ & therefore myocardial O2.
Can plasma NT-proBNP measurement be affected by strenuous exercise in dogs?
Hunt JVIM 2018
Yes - can exceed upper RI
What are microRNA?
Changes in which 3 miRNAs were observed in dogs receiving doxorubicin, and which miRNA was useful for documenting doxorubicin cardiotoxicity in these dogs?
Beaumier JVIM 2020
MicroRNA bind RNA and prevent signal translation; very stable - potentially useful as biomarkers.
Dogs receiving doxo - miR-107 & miR-146A sig downregulated, miR-502 sig upregulated.
Biomarker for doxorubicin cardiotoxicity in dogs. Significant changes in miR-502 occurred before 3rd chemo dose. miRNA changes preceded cTnI elevations (latter only occurred after completing chemo course).
a) What are the functional differences between classic & alternative angiotensin peptides (AP) in the context of heart failure? Name examples of these APs.
b) Describe how alternative APs are formed.
c) Which treatment group of dogs with DMVD had the most favourable AP profile?
i) ARB + ACE2
ii) ARB only
iii) ACE-I only
iv) ACE-I + ACE2
Larouche-Lebel JVIM 2020
a) Classic APs mediate vasoconstriction, Na retention, congestion, cardiac remodelling»_space; promote CHF. E.g. Angiotensin (AT) 2, AT3, AT4, AT2-receptor type 1
Alternative APs mediate vasodilation, natriuresis, diuresis, anti-remodelling > cardioprotective. E.g. Ang1-5, Ang1-7 (best studied), Ang1-9.
b) ACE2 enzyme removes a single AA from AT1 or AT2 to form Ang1-9 & Ang1-7 respectively.
c) i) ARB + ACE2
What effects did combined treatment of recombinant human ACE2 (rhACE2) & ARB (telmisartan) have on the RAAS profile of cats with cardiomyopathy?
Huh JVIM 2020
Combo tx sig increased Ang1-7 & other alternative APs in CM cats –> cardioprotective.
(ARB tx alone also sig increased Ang1-7 but to a smaller degree vs combo tx).
- What is angiotensin-converting enzyme 2 (ACE2)?
- Does plasma ACE2 activity change in dogs with CHF vs dogs with preclinical cardiac disease?
- What effects did recombinant human ACE2 (rhACE2) treatment have on the RAAS profile of dogs with cardiac disease?
Larouche JVIM 2019
1. ACE2 = homologue of ACE, produces angiotensin peptides (APs) e.g. Ang1-9 & Ang1-7 that are vasodilatory and natriuretic –> act to counterbalance AT-II.
2. Yes - plasma ACE-2 & benefical APs (esp Ang1-7) are increased in dogs with CHF (~10x preclinical dogs).
3. rhACE2 increased beneficial APs (e.g. Ang1-9) while simultaneously decreasing maladaptive APs (e.g. AT-II).
What is the dose-response relationship for ACEI in dogs with cardiac disease?
Ward JVIM 2021
q12hr dosing & higher K+ at the first revisit were predictive of 2 year survival. q12hr dosing may optimize cardioprotective benefits of ACEI.
What is speckle tracking echocardiography? What changes can be seen in HCM cats?
Spalla JVIM 2019
Allows quantification of myocardial deformation in the longitudinal, radial, and circumferential planes; and can provide info on regional & global myocardial function.
Cats with HCM had increased LV mass, decreased systolic long axis (longitudinal deformation) & radial deformation, but overall preserved circumferential strain & strain rate.
What is the prevalence of cardiac cachexia in cats, based on MCS? What other factors is it associated with? Does it have a prognostic impact?
Santiago JVIM 2020
41.6% prevalence. Associated with older age, pleural effusion, lower HCT/Hb, higher neutrophils, higher BUN, lower BCS.
Shorter survival time vs non-cachexic cats.
What criteria on POC lung US (LUS) increases suspicion of cardiogenic pulmonary oedema compared to non-cardiac causes of dyspnea in dogs & cats based on a 2017 study?
Accuracy of POCUS findings in differentiating cardiac vs non-cardiac causes?
Ward JAVMA 2017
POCUS - positive site defined by > 3 B-lines at site. ≥ 2 positive sites on each hemithorax.
Dogs/cats with CPO had higher # of positive LUS sites vs non-cardiac causes.
Sn 84%, spec 74% (similar to TXR - Sn 85%, spec 87%).
False positives most common with diffuse interstitial or alveolar disease - not useful to differentiate in these cases.
- What echo parameter is typically used to predict pulmonary hypertension (PH)? Include relevant formula in your answer.
- What alternative echo variable may be useful to predict PH if the above parameter cannot be measured? What is the cutoff for the highest predictive accuracy?
Visser JVIM 2016
1. Tricuspid regurgitation velocity (TR Vmax). Modified Bernoulli equation: PAP = 4 x (TR Vmax)^2
(Also can use pulmonic regurg velocity)
2. Right pulmonary artery distensibility (RPAD) - strong negative correlation to tricuspid regurgitation
Cut-off <29.5%, Sn 84%, Sp 95% to predict TRPG >50mmHg
Other echo parameters (in order of correlation): Main PA size: aorta size (MPA:Ao) > acceleration time to peak PA flow (AT)> AT: ejection time of PA flow (AT:ET).
Is cisterna chyli ablation helpful in addition to thoracic duct ligation + subphrenic pericardectomy in cats with idiopathic chylothorax?
Stockdale JAVMA 2018
No. Increased surgical time but without better outcomes (no sig diff in MST).
The SECOND generation point-of-care (POC) & quantitative NT-proBNP tests were evaluated in cats with pleural effusions. Which tests on which sample types were/were not sensitive/specific to differentiate CHF from other causes?
Hezzell JVIM 2016
- Quantitative ELISA was Sn & Sp for both plasma (95% Sn, 82% Sp) + pleural effusion (100% Sn, 76.5% Sp), with different cut-offs (higher proBNP concentrations in PLEURAL FLUID vs plasma). Notably highly sensitive but moderately specific.
- POC test was useful for PLASMA samples (Sn 95%, Sp 87%), but for pleural fluid had high Sn (100%) but poor specificity (64%).
- Similar diagnostic accuracy with 1st gen ELISA assays.
- What does Lights criteria use for the characterisation of pleural effusion in cats?
- What parameter is useful to differentiate exudates from transudates in cases with discordant classification based on clinical vs Light’s criteria?
Zoia JFMS 2016
Pleural fluid to serum lactate dehydrogenase (LDH) & TP ratios.
Lactate ratio 0.6+ & TP ratio 0.5+ consistent with exudate.
- Albumin gradient (ALBg). Some CHF cats will be “exudative” on Lights criteria but clinical criteria = transudate. Gradient will help differentiate. NB: classic exudate cut of: 30+g/L and >7K cells/uL. Transudate <25g/L, < 1500K cells/uL.
NB: original paper on Lights Criteria - Zoia JFMS 2009.
Pleural fluid lactate dehydrogenase concentration (LDHp) & pleural fluid/serum total protein ratio (TPr)) were most reliable in differentiating transudates & exudates (Sn 100% & 91%, Sp 100%). Also evaluated serum/fluid cholesterol ratio, glucose & TNCC.
What parameters do the simplified Light’s Criteria measure?
How useful was this in differentiating causes of pleural effusion in DOGS, as compared to traditionally measured parameters (Fluid TP & TNCC)?
Zoia Vet Rec 2020
Pleural effusion lactate dehydrogenase concentration & serum TP.
LC had 98% diagnostic accuracy (vs 57% for traditional classification) in discriminating exudates from transudates. Fluid TNCC & TP had poor diagnostic utility.
What 2 clinical parameters are potentially useful from a retrospective study in cats with pleural effusion associated with CHF and/or neoplasia?
Ruiz JAVMA 2018
Rectal temperature - lower in CHF cats (36.9 vs 37.9)
Age - CHF & neoplasia more likely in older cats (LSA cats significantly younger cf carcinoma).
What metabolic derangement is associated with hypertension & proteinuria in Greyhounds?
Martinez JVIM 2016
Altered plasma eicosanoid profiles - consistent with activation of metabolite pathways that promote vascular dysfunction & contribute to higher BP & albuminuria.
- Hypertension correlated with higher 11,12EET & 20(S)HETE
Hydroxyeicosatetraenoic acid = HETE, epoxyeicosatrienoic acid = EET
- Albuminuria correlated with total DHET (higher in greyhounds) Dihydroxyeicosatrienoic acid = DHET
How do you measure vertebral LA size on radiographs, and what cut-off is consistent with LA enlargement? Does this correlate with LA: Ao?
Malcolm JAVMA 2018
Right lateral thoracic radiograph.
1st line - measure from carina to the caudal aspect of LA where intersects with the CVC dorsal border.
2nd line (equal length to 1st) - measure from cranial edge of T4 caudally - to get no. of vertebrae included in this length.
LA = 2.3+ vertebrae - predictive of LA enlargement. Repeatable & reliable correlation with LA:Ao.
What is the median no. of VPC/24hrs in healthy Salukis based on a 7-day Holter monitoring?
Sanders JAVMA 2018
2
Sotalol MOA, onset to effect & indications?
What is the effect of sotalol on echo features of ventricular function in dogs with ventricular arrhythmias?
Visser JVIM 2018
Class III anti-arrhythmic. K channel blocker + non-selective beta-adrenergic receptor blocker.
Rapid absorption, peak plasma [ ] within 2-4hrs post pill, so can be useful to acutely terminate arrhythmias in hemodynamically stable dogs. Main indication is chronic tx of ventricular arrhythmias.
Mild decrease in LV systolic function. Caused decreases in all systolic function indices except TAPSE; but only % changes in LVIDs (normalised) & ejection fraction (EF) were significantly different.
(NB LVIDs INCREASES with systolic dysfunction).
No adverse events, even in dogs with LA enlargement or systolic dysfunction.
Which atrial tachyarrhythmia may lignocaine be efficacious for? In what % of dogs did cardioversion take place?
How does this atrial tachyarrhythmia arise & what are supportive ECG findings?
Wright JVIM 2019
Orthodromic AV reciprocating tachycardias (OAVRT).
84% converted with median total dose 2mg/kg (2-5.5).
The typical accessory pathway (AP) is composed of myocardial cells spanning the fibrous AV function, and provide electrical continuity between A & V myocardium at distinct sites from SV node & proximal His-Purkinje system. Failure of these pathways to regress forms the substrate for APs. APs can facilitate retrograde conduction, from V to A myocardium, allowing a macroreentrant tachycardia circuit. AP cells share ultrastructural similarities with ventricular myocardial cells.
ECG findings - regular, narrow QRS complex tachycardia that terminates in the face of 2nd deg AV block.
What dog breed is commonly affected by AV accessory pathways? What are common characteristics of this condition?
What is the recommended treatment and outcome in these dogs?
Wright JVIM 2018
Labradors 47%, male (67%).
CSx: lethargy & GI signs, also tachycardia-induced cardiomyopathy in 46% (see DCM phenotype).
Right-sided APs (92%) > L.
Radiofrequency catheter ablation eliminated AP conduction long term in 98.8% of dogs, recurrence eliminated with a 2nd procedure in small % of dogs.
What % of dogs with AVBs undergoing pacemaker implantation had regression to more normal rhythms, and in what timeframe did this occur?
Santilli JVIM 2016
14% (7/48) of dogs regressed, typically within 30days after pacemaker implantation. 86% had static or progressive paroxysmal AVBs. Progression occurred at any time, so degree of AVB at the time of PMI should not be considered definitive, requires ongoing monitoring.
Most dogs that did not improve had chronic structural (fibrous/fibrous-fatty change to AV bundle. The dogs that improved could have had myocarditis (reported as cause of transient AVB).
What is pentamidine analogue 6 (PA-6)? How does it work?
What was it evaluated for use in dogs, and what was the outcome?
Szatmári JVIM 2018
Inhibitor of the inward rectifier K+ current (IK1), which is important for depolarisation & maintaining RMP (at -90mV) + contributes to phase 3 repolarization. In experimental AFib models this K+ channel is upregulated, so this drug was proposed to be effective for AFib.
Evaluated in large breed dogs with AFib. Protocol was IV bolus 2.5 mg/kg over 10min then maintenance CRI 0.04 mg/kg/min for max 50mins. None cardioverted to sinus rhythm.
Self-limiting SE: VPC, respiratory distress with laryngeal stridor, muscular weakness & twitching.
(3 papers)
What is the prognostic implication of HR in dogs with AFib? Specifically, how much will an increase in HR by 10bpm increase mortality by? What HR threshold was used for survival comparison?
Was findings similar/different when compared to a separate study evaluating AFib in non-small breed dogs with MMVD & CHF?
What was the prevalence of sudden cardiac death in dogs with AFib? What were associated risk factors?
Pedro JVIM 2018
* For every 10bpm increase, risk of all-cause mortality increased by 35%.
* MST longer in dogs with HR <125bpm (1037d vs 105d if HR 125+).
* Mean HR was independently associated with all-cause & CVS-related mortality.
Jung JVIM 2016
* Simliar findings, AF increased risk of cardiac death.
* MST 142d for AF (vs 234d w/o AF)
* Inadequately controlled AF associated with increased risk of mortality.
* Diltiazem + digoxin combo significantly decreased HR & prolonged MST (130d) cf diltiazem (35d) alone.
Borgeat JVIM 2021
14.8% (vs 5.5% controls).
Younger age at dx, larger LA, syncope.
What drug (Pimobendan, digoxin or benazepril) was associated with delaying CHF or death in Irish Wolfhounds with cardiomyopathy associated with AF or DCM?
Vollmar JVIM 2016
Pimobendan. Reached study endpoint in 1991d (digoxin 1263d, benazepril 997d).
What are the different PDA types & how does the PDA type impact treatment recommendations?
What PDA anatomical type is most commonly reported in GSDs?
Why is transoesophageal echocardiography recommended?
Wesselowski JVIM 2019
PDA phenotypes classified based on angiography. Types I, IIa, IIb, III. IV, V.
Type III PDAs (tubular appearance with minimal-no tapering in ductal diameter before insertion into the PA) are not amenable to interventional procedures (e.g. Amplatz canine duct occluder placement; instead surgical ligation is performed to avoid device-related complications due to inadequate device stability).
Type II anatomy most common in GSDs (88%).
3/24 dogs had unusual anatomy in this study (types IV & V), with median minimal ductal diameter was larger than in a mixed dog population, hence recommend echo for optimal procedural planning.
What is the most common PDA morphology & how is it best visualised?
Doocy JVIM 2018
3D Transoesophageal echocardiography (TEE-3D). Oval shape.
Does PDA size correlate with body weight?
Wesselowski JVIM 2017
Poor correlation, not recommended to base choice of occluder on BW. in small patients the femoral artery size can limit the size of device used (see paper on Amplatz plug Type 4).
Is pulmonary hypertension a contraindication to PDA closure?
Boutet JVIM 2017
No. pulmonary hypertension was not seen in this study but still associated with L-R shunts. Adult dogs in this study and improvement was seen with PDA closure, even when clinical.
Name 1 characteristic PE finding & 1 bloodwork abormality in dogs with pulmonary hypertension (PHT) associated with reverse R-L PDA shunts.
Is PHT a contraindication to PDA closure in dogs?
Can older dogs (>5yo) presenting with clinical signs & cardiac remodelling associated with PDA still benefit from closure?
Boutet JVIM 2017
Differential cyanosis. (blue/purple caudal MM, pink cranial MM). Polycythemia (renal response to hypoxia) > seizures if severe.
No. Pulmonary hypertension is not a contraindication for closure as long as it does not cause complete R-L (reverse) shunting.
Yes. Adult dogs presenting with L-R PDA later in life (5+yo) resulting in cardiomegaly & clinical signs can still improve or resolve with PDA closure.
