OBJECTIVE To evaluate the diagnostic utility of ECGs acquired with a smartphone-based device, compared with reference 6-lead ECGs, for identification of heart rate and rhythm in dogs and cats.
DESIGN Prospective study.
ANIMALS 51 client-owned dogs and 27 client-owned cats.
PROCEDURES Patients examined by a small animal referral cardiology service between April 2012 and January 2013 were enrolled consecutively. In each patient, a 30-second ECG was simultaneously acquired with a smartphone-based device (a bipolar, single-lead recorder coupled to a smartphone with an ECG application) and a standard 6-lead ECG machine. Recordings were evaluated by 3 board-certified cardiologists, and intra- and interobserver agreement were evaluated for both rhythm diagnosis and QRS polarity identification.
RESULTS Values for instantaneous and mean heart rates for the smartphone-acquired and reference ECGs were within 1 beat of each other when mean heart rates were calculated. Intraobserver agreement for rhythm assessment was very high, with maximum disagreement for any observer for only 2 of 51 dogs and only 4 of 27 cats. There was minimal disagreement in the polarity of depolarization between the smartphone-acquired and reference ECGs in dogs but frequent disagreement in cats. Interobserver agreement for smartphone-acquired ECGs was similar to that for reference ECGs. with all 3 observers agreeing on the rhythm analysis and minimal disagreement on polarity.
CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that ECGs acquired with the smartphone-based device accurately identified heart rate and rhythm in dogs and cats. Thus, the device may allow veterinarians to evaluate and manage cardiac arrhythmias relatively inexpensively at the cage side and could also allow clinicians to rapidly share information via email for further consultation, potentially enhancing patient care.
Objective—To determine electrocardiographic parameters
in healthy llamas and alpacas.
Animals—23 llamas and 12 alpacas.
Procedure—Electrocardiography was performed in
nonsedated standing llamas and alpacas by use of multiple
simultaneous lead recording (bipolar limb, unipolar
augmented limb, and unipolar precordial leads).
Results—Common features of ECGs of llamas and
alpacas included low voltage of QRS complexes, variable
morphology of QRS complexes among camelids,
and mean depolarization vectors (mean electrical
axes) that were directed dorsocranially and to the
right. Durations of the QT interval and ST segment
were negatively correlated with heart rate.
Conclusions and Clinical Relevance—ECGs of
acceptable quality can be consistently recorded in
nonsedated standing llamas and alpacas. Features of
ECGs in llamas and alpacas are similar to those of other
ruminants. Changes in the morphology of the QRS
complexes and mean electrical axis are unlikely to be
sensitive indicators of ventricular enlargement in llamas
and alpacas. (Am J Vet Res 2004;65:1719–1723)
Objective—To compare cardiac troponin I (cTnI) concentrations determined by use of a point-of-care analyzer with values determined by use of a bench-top immunoassay in plasma samples obtained from clinically normal horses with and without experimentally induced cardiac disease, and to establish a reference range for plasma equine cTnI concentration determined by use of the point-of-care analyzer.
Animals—83 clinically normal horses, 6 of which were administered monensin to induce cardiac disease.
Procedures—A blood sample was collected from each of the 83 clinically normal horses to provide plasma for analysis by use of the point-of-care analyzer; some of the same samples were also analyzed by use of the immunoassay. All 83 samples were used to establish an analyzer-specific reference range for plasma cTnI concentration in clinically normal horses. In 6 horses, blood samples were also collected at various time points after administration of a single dose of monensin (1.0 to 1.5 mg/kg) via nasogastric intubation; plasma cTnI concentration in those samples was assessed by use of both methods.
Results—The analyzer-specific reference range for plasma cTnI concentration in clinically normal horses was 0.0 to 0.06 ng/mL. Following monensin treatment in 5 horses, increases in plasma cTnI concentration determined by use of the 2 methods were highly correlated (Pearson correlation, 0.83). Peak analyzer-determined plasma cTnI concentrations in monensin-treated horses ranged from 0.08 to 3.68 ng/mL.
Conclusions and Clinical Relevance—In horses with and without experimentally induced cardiac disease, the point-of-care analyzer and bench-top immunoassay provided similar values of plasma cTnI concentration.
Objective—To evaluate whether administering a tart cherry juice blend (TCJB) prior to exercise would reduce skeletal and cardiac muscle damage by decreasing the inflammatory and oxidative stress response to exercise in horses.
Procedures—Horses were randomly allocated into 2 groups in a crossover study with a 2-week washout period and orally administered either TCJB or a placebo solution (1.42 L, twice daily) in a double-masked protocol for 2 weeks prior to a stepwise incremental exercise protocol. Horses were tested for serum activities of creatine kinase and aspartate aminotransferase (AST) and concentrations of cardiac troponin I (cTnI), thiobarbituric acid reactive substances (TBARS; an indicator of oxidative stress), and serum amyloid A (SAA; an indicator of inflammation). To ensure that treatment would not result in positive results of an equine drug-screening protocol, serum samples obtained from each horse prior to and after 2 weeks of administration of TCJB or the placebo solution were tested.
Results—All horses had negative results of drug screening at both sample times. The exercise protocol resulted in a significant increase in TBARS concentration, SAA concentration, and serum AST activity in all horses. Administration of TCJB or placebo solution was not associated with an effect on malondialdehyde or SAA concentrations. However, administration of TCJB was associated with less serum activity of AST, compared with administration of placebo solution.
Conclusions and Clinical Relevance—Administration of TCJB may diminish muscle damage induced by exercise.
Objective—To determine the type of atrial fibrillation induced by use of 2 pacing protocols during fentanyl and pentobarbital anesthesia before and after administration of atropine and to determine the organization of electrical activity in the left and right atria during atrial fibrillation in German Shepherd Dogs.
Animals—7 German Shepherd Dogs.
Procedures—Extrastimulus and pacedown protocols were performed before and after atropine administration. Monophasic action potential spectral entropy and mean dominant frequency were calculated during atrial fibrillation.
Results—Atrial fibrillation occurred spontaneously in 6 of 7 dogs. All 7 dogs had atrial fibrillation induced. Sustained atrial fibrillation occurred in 13 of 25 (52%) episodes induced by the extrastimulus protocol and in 2 of 12 episodes of atrial fibrillation induced by pacedown. After atropine administration, sustained atrial fibrillation did not occur, and the duration of the nonsustained atrial fibrillation (6 episodes in 2 dogs of 1 to 26 seconds) was significantly shorter than before atropine administration (25 episodes in 7 dogs of 1 to 474 seconds). The left atrium (3.67 ± 0.08) had lower spectral entropy than the right atrium (3.81 ± 0.03), indicating more electrical organization in the left atrium. The mean dominant frequency was higher in the left atrium in 3 dogs.
Conclusions and Clinical Relevance—Atrial fibrillation developed spontaneously and was induced in German Shepherd Dogs under fentanyl and pentobarbital anesthesia. Electrical activity was more organized in the left atrium than in the right atrium as judged by use of spectral entropy.