Electrocardiographic values for anesthetized cats in lateral and sternal recumbencies.
Explore the source record for details and available documents.
Anesthesia↗
Biomedical subjects
C A Calvert
Publications and source records attributed to C A Calvert.
Echocardiographic detection of flail left atrioventricular valve cusp from ruptured chordae tendineae in 4 dogs.
Echocardiography was used to identify a flail left atrioventricular valve cusp caused by ruptured chordae tendineae in each of 4 dogs; two-dimensional echocardiography was superior to M-mode echocardiography in identifying the flail cusps. The following findings on two-dimensional imaging were characteristic: the tip of the flail cusp extended beyond the line of left atrioventricular valve cusp closure and pointed toward the left atrium in systole; the tip was thrust into the left ventricle, and then toward the left ventricular outflow tract in diastole, forming a convex surface to the cusp, which faced toward the left ventricle. The flail motion of the left atrioventricular valve cusp was best observed in the right parasternal long axis or left apical four-chamber views, in a plane parallel to the long axis of the left ventricle and left atrium. Rupture of chordae tendineae leading to flail cusp was attributed to chronic valve degeneration (endocardiosis) in all 4 dogs. Echocardiographic or clinical diagnoses were confirmed by postmortem gross and microscopic studies in all dogs.
Animals↗
Bradycardia-associated episodic weakness, syncope, and aborted sudden death in cardiomyopathic Doberman Pinschers.
Paradoxical sinus bradycardia and cardiac asystole resulted in episodic weakness, syncope, or aborted sudden cardiac death during exertion in 8 cardiomyopathic Doberman Pinschers. Bradycardias persisted for 1 to 2 minutes in 5 of 8 dogs, and were often followed by sinus tachycardia. Syncope was prolonged on multiple occasions in 5 dogs, and was accompanied by white, then cyanotic mucous membranes, mydriasis, and apparent sudden death.
Animals↗
Efficacy and toxicity of tocainide for the treatment of ventricular tachyarrhythmias in Doberman pinschers with occult cardiomyopathy.
Tocainide was administered to 23 cardiomyopathic Doberman Pinschers at doses of 15 to 25 mg/kg tid. These doses produced peak (2-hour) serum concentrations of 6.2 to 19.1 mg/L and trough (8-hour) serum concentrations of 2.3 to 11.1 mg/L. Anorexia and gastrointestinal disturbances occurred in 8 dogs (35%) at doses (15.6 to 25.0 mg/kg) that were not different from those (16.0 to 26.0 mg/kg) received by dogs that did not experience toxicity. Doses producing peak serum concentrations that were either greater or less than 14 mg/L were not different. Likewise, doses producing trough values that were either greater or less than 6 mg/L were not different. The mean dose that produced peak serum concentrations of 10 to 13.6 mg/L and trough concentrations of 4.2 to 10.0 mg/L was 17.9 mg/kg, and was associated with anorexia in 4 dogs. Mean peak serum concentrations associated with toxicity (14.4 mg/L) were significantly higher (P = .02) than dogs not experiencing toxicity (11.8 mg/L). Serious adverse effects occurred in 7 of 12 dogs (58%) receiving tocainide for longer than 4 consecutive months. Progressive corneal endothelial dystrophy occurred in 3 dogs. Although a causal effect could not be proven, 6 dogs experienced renal dysfunction during treatment. Drug doses in these 7 dogs were similar to those received by other dogs. At least a 70% reduction of the total numbers of ventricular premature contractions occurred in 80% of dogs treated, and ventricular tachycardia was eliminated in 90% of affected dogs by the time of the first posttreatment Holter recording. Long-term control of ventricular tachyarrhythmias was difficult to achieve in some dogs when the left ventricular shortening fraction was less than approximately 17%.
Animals↗
Signalment, survival, and prognostic factors in Doberman pinschers with end-stage cardiomyopathy.
Congestive heart failure (CHF) was evaluated by retrospective review of case records of 66 Doberman Pinschers presenting with overt signs of 2 weeks' duration or less. Left-sided CHF was predominant, the majority of dogs were male, most were 5 to 10 years of age, and CHF tended to occur in females at an older age. Sudden death occurred in 13 dogs (20%). The mean and median survival times of all dogs were 9.65 and 6.5 weeks, respectively. Both atrial fibrillation and bilateral CHF at the time of presentation were associated with significantly shorter survival times.
Age Factors↗
Possible late potentials in 4 dogs with sustained ventricular tachycardia.
Signal-averaged electrocardiograms (SAEKGs) were performed on 4 dogs with sustained ventricular tachycardia. Quantitative and qualitative analyses of SAEKGs were consistent with the presence of late potentials. Two of the 4 dogs subsequently died suddenly, and ventricular tachycardia and ventricular fibrillation were observed in 1 dog. High-frequency QRS durations (75-90 milliseconds), duration of low amplitude (less than 40 microV) signals during the terminal QRS complex (LAS40) (28-40 milliseconds), root mean square voltages of the terminal 40 milliseconds of the QRS complex (RMS40) (124-6.5 microV), and root mean square voltages of the terminal 30 milliseconds of the QRS complex (RMS30) (13-2.1 microV) differed from results obtained in 68 of 70 control dogs. Echocardiographic data suggested dilated cardiomyopathy in 2 dogs and the cause of the arrhythmia in 2 dogs was not determined. The SAEKG may be a useful adjunct in identifying a subset of dogs with ventricular tachyarrhythmias that are at high risk for sustained ventricular tachycardia and sudden death. The sensitivity, specificity, and predictive accuracies of the technique remain to be determined.
Animals↗
Thyroid-stimulating hormone stimulation tests in cardiomyopathic Doberman pinschers: a retrospective study.
Thyroid-stimulating hormone (TSH) response tests were performed in 152 Doberman Pinschers. Seventy-nine dogs had cardiomyopathy (46 were in congestive heart failure [CHF] and 33 were not in CHF). Seventy-three dogs were presented for noncardiac problems (15 with skin disease, 21 with neurologic disease, 20 with internal medicine disorders, and 17 with other problems), although some may have had cardiomyopathy. The TSH response test results in the cardiomyopathic group were interpreted as normal or euthyroid-sick in 45 (57%) dogs, abnormal in 23 (29%) dogs, and equivocal in 11 (14%) dogs. The prevalence of hypothyroidism in the CHF and non-CHF cardiomyopathy groups was not different. Among the dogs presented for noncardiac problems, 27 (37%) were assessed as normal or euthyroid-sick, 29 (40%) as hypothyroid, and 17 (23%) as equivocal. No significant differences were found in the prevalence of hypothyroid test results among the subgroups of these dogs. The prevalence of hypothyroidism was not higher in the cardiomyopathic group compared to the other group, and 63 and 49% of cardiomyopathic dogs with or without CHF, respectively, tested as either euthyroid or euthyroid-sick.
Animals↗
Signal-averaged electrocardiograms in normal Doberman pinschers.
Signal-averaged electrocardiograms (SAECGs) were performed on nonsedated normal dogs in left-lateral recumbency. Following signal averaging, both time-domain and 3-dimensional frequency-domain analyses were performed. For time-domain analysis, the high-frequency QRS (HFQRS) duration, duration of the terminal QRS complex less than 40 microV (LAS40), and root mean square (RMS) voltages (microV) of the terminal 40 milliseconds (RMS40) and 30 milliseconds of the QRS complex were calculated. For frequency-domain analysis, correlation ratios were calculated for 30-, 40-, 50-, and 60-millisecond segment lengths begun 10, 15, or 20 milliseconds before the end of the QRS complex. Spectro-temporal mapping was also performed. All of the parameters of the SAECGs analyzed in the time domain were associated with each other. LAS40 and RMS voltages regressed significantly (P < .0000) on the HFQRS duration. Ninety-five percent of the HFQRSs were 55-75 milliseconds, 95% of the LAS40s were 9-26 milliseconds, and 95% of the RMS40 voltages were 177-444 microV. None of the SAECGs contained evidence of ventricular late potentials. Spectro-temporal maps were similar in each dog when the same segment lengths and starting points were compared. No evidence of ventricular late potentials was observed. Correlation ratios were lower when windowed segments included 15 or 20 milliseconds (versus 10 milliseconds) of the terminal QRS complex. When only 10 milliseconds of the terminal QRS complex were included in windowed segments, the mean correlation ratios for 30- and 40-millisecond segment lengths were > 0.8 and > 0.61 in 67% of all analyses, respectively.
Animals↗
Unfavorable influence of anesthesia and surgery on Doberman pinschers with occult cardiomyopathy.
Exacerbation of heart rhythm disturbances or deterioration of left-ventricular function occurred in six Doberman pinschers with occult cardiomyopathy following anesthesia and surgery. These abnormalities improved over time in surviving dogs, supporting a causal relationship between anesthesia/surgery and exacerbation. Moderate myocardial failure and ventricular tachyarrhythmias of variable severity existed prior to anesthesia and surgery in each dog. The incidence of these adverse effects is uncertain but probably significant. Exacerbation of arrhythmias may be life-threatening or lethal. Embarrassment of left-ventricular function may be inapparent or, if function already is marginal, may precipitate congestive heart failure.
Anesthesia↗
Feline diabetes mellitus: a retrospective mortality study of 55 cats (1982-1994).
Signalment, concomitant diseases, prognostic factors, and mortality were evaluated, retrospectively, in 55 diabetic cats (mean age, 11 years; range, five to 18 years). Sixty-seven percent of the cats were between 7.5 and 15 years of age. One-year mortality (n = 23) was high; most early deaths were due to comorbid disease, and the rate of death diminished in cats surviving beyond one year. The median survival time for all cats was 29 months; among cats that died, the median survival time was 11 months. Of the cats surviving more than one year, 16 were alive at a mean of 41 months. Only 13 of 37 cats died due to diabetes mellitus; the majority died due to concomitant diseases, with renal failure (n = 8) and hepatopathies (n = 6) being the most common causes. No clinical data was identified as being of prognostic significance.
Animals↗
Hypertrophic cardiomyopathy in a litter of five mixed-breed cats.
A litter of five, 18-month-old, mixed-breed cats were determined to have hypertrophic cardiomyopathy (HCM). Although no overt clinical signs were present in any cat, systolic heart murmurs were present in each. Electrocardiograms were normal, while subjective interpretations of heart enlargement on radiographs were made on four cats. Echocardiographic analyses indicated abnormalities consistent with HCM. Overt clinical signs are absent two years following diagnosis.
Animals↗