Introduction
Symptomatic bradyarrhythmias unresponsive to medical treatment remain the most common indication for artificial cardiac pacing (ACP) in cats.1–3 The primary bradyarrhythmias requiring ACP are atrioventricular blocks (AVBs), including intermittent and persistent third-degree AVB and high-grade second-degree AVB,2,4–11 as well as atrial standstill.9,12
In dogs, transvenous pacemaker implantation is generally the preferred method of ACP, while in cats, epicardial pacemaker (EP) placement through a thoracotomy or median celiotomy with a transdiaphragmatic approach is more common.1–3,6,7,10,12 Transvenous pacemaker implantation has been reported in only 5 cats5–9 due to the small patient size, limited vascular access relative to the size of available endocardial leads, and a higher risk of endocardial complications such as a higher propensity for vascular thrombosis3,11,13 or chylothorax.9
Artificial cardiac pacing is less commonly indicated in cats than in dogs, as cats are believed to tolerate bradyarrhythmias better than dogs and are less susceptible to sudden death. This is assumed to be because their ventricular escape rhythm rate is often similar to their resting sinus rhythm.2–4,6,9,12,14 Consequently, EP implantation is typically reserved for cats showing clinical signs such as syncope, lethargy, or congestive heart failure (CHF) that affect their quality of life.2–4,6,9,12,14 Colpitts et al4 reported a high likelihood of resolution of clinical signs after EP implantation in cats with AVB; however, similar survival times were noted between cats that received an EP and asymptomatic cats that did not, suggesting the ACP might not be indicated in asymptomatic cats. Outcomes of cats treated with or without ACP for AVB have been reported to be comparable, although ACP can improve the subjective quality of life for some cats.4,12
A recent study15 in dogs showed that EP implantation led to improved clinical signs and significantly increased activity levels, willingness to play, and overall health-related quality of life (HRQoL).
Evaluation of HRQoL is essential for the assessment of treatment outcomes in veterinary medicine. Increasingly, the focus is on quantifying anticipated HRQoL improvement to inform clinical decisions for patients and support owners in choosing treatment options.16–19 Such assessment extends beyond traditional survival metrics, providing a comprehensive understanding of the patient’s response to interventions and the effectiveness of treatments. Consequently, HRQoL measures are recognized as critical determinants of therapeutic success, serving as essential end points alongside mortality rates.16–19
The objectives of this study were as follows: (1) to describe complications and outcomes of cats undergoing EP implantation by use of a large-scale multicenter study and (2) to use an HRQoL questionnaire to determine improvements in clinical signs and HRQoL after EP implantation in cats. We hypothesized that outcomes for cats undergoing EP implantation would be good and owners would report an improvement in their cats’ HRQoL after EP placement.
Methods
This retrospective observational study used anonymized clinical data and was approved by the social science research ethical review board of the Royal Veterinary College, University of London (approval No. URN SR2021-0213). Ethical reviews were also conducted at the University of Bristol (VIN/22/010) and University of Liverpool (VREC1234).
Data collection
Electronic records from 4 small animal referral hospitals between July 2010 and December 2022 (Royal Veterinary College, University of Liverpool, University of Bristol, and North Downs Specialist Referrals) were searched to identify cats that had an EP placed. The search terms epicardial pacemaker AND cat were used, and cases were reviewed for inclusion by the authors. Cats were excluded from the study if their medical records contained incomplete descriptions of diagnostic findings, surgical detail, or follow-up data or if they had a transvenous pacemaker implanted. Data collected from the records included signalment, clinical history, presenting clinical signs, presence or absence of coexisting cardiac pathology, ECG diagnosis, time from diagnosis to EP placement, presence of concurrent medical conditions (cardiac and noncardiac), reason for EP placement, anesthetic and surgical time, surgical approach, method of lead fixation, pacing mode, location of the generator, and details on thoracostomy tube placement. The occurrence of any intraoperative and postoperative complications was recorded as well as the requirement of additional surgical intervention or medical treatment; these were classified according to Follette et al20 and are described in Table 1. For each cat, survival time was determined as the time elapsed from the date of EP placement to the date of death, euthanasia, or loss to follow-up.
Classification of complications according with Follette et al.20
| Level | Definition |
|---|---|
| Mild | Requires only minor invasive procedures that can be performed at bedside such as insertion of IV lines, urinary catheters, nasogastric tubes, and drainage of wound infections. Physiotherapy and the following. drugs are allowed: antiemetics, antipyretics, analgesics, diuretics, and electrolytes. |
| Moderate | Requires pharmacologic treatment with drugs other than those allowed for minor complications (eg, antibiotics); blood transfusions and total parenteral nutrition are also included. |
| Severe | All complications requiring endoscopic or interventional radiologic procedures or reoperation as well as complications resulting in failure of 1 or more organ systems. |
| Death | Postoperative death. |
Health-related quality of life questionnaire
To evaluate outcome, a 2-part (preoperative and long-term follow-up) questionnaire was designed (Supplementary Material S1) on the basis of a previously published HRQoL questionnaire for dogs with congenital portosystemic shunts and cardiac diseases.15–18
For the assessment of clinical signs, 6 questions for the preoperative part and 8 questions for the long-term follow-up part were developed on the basis of previously reported clinical signs associated with cardiac pathologies that required ACP and complications reported after transvenous pacemaker and EP implantation.12,15,21,22 For each clinical sign, the frequency was recorded on a categorical scale (never, less than once a month, weekly, and daily) and the impact on the cat’s quality of life was recorded with a visual analogue scale (VAS) from not at all to could not be worse.
Five questions in both parts of the questionnaire were designed to assess the cat’s activity levels and willingness to exercise, play, and interact with the owner or other pets. These questions used a VAS from not willing at all to could not be more willing. In the long-term follow-up part of the questionnaire, 6 questions were designed to assess the outcome of the procedure, the owners’ satisfaction or concerns, and the improvement of the cat’s HRQoL.
Statistical analysis
Analyses were performed with Excel 2020 (Microsoft Corp) and SPSS Statistics (version 28.0; IBM Corp). The level of statistical significance was set at P < .05. Descriptive statistics were computed for all variables. On the basis of results of the Shapiro-Wilk test, none of the continuous explanatory variables were likely to be from a normal distribution (P < .001 for all), so they are reported as median with the IQR.
For the questionnaire data, individual preoperative and long-term follow-up question scores were compared with the Wilcoxon signed-rank test. Only owners who completed both questionnaires were included in the statistical analysis. The median survival time (MST) and corresponding 95% CIs were calculated with the Kaplan-Meier survival analysis.
Results
Population data, clinical presentation, and diagnostic investigations
Thirty-nine cats met the inclusion criteria. The population included 19 neutered female and 20 neutered male cats. The most common type of cats was mixed breed, including domestic shorthair (n = 25) and domestic longhair (2). Pure-breed cats represented the additional 12 cats: Persian (n = 2), Bengal (2), Norwegian Forest (2), Tiffany (1), Ragdoll (1), Birman (1), Devon Rex (1), British Shorthair (1), and Abyssinian (1).
At the time of the surgery, the median age was 12 years (IQR, 9 to 14 years) and the median weight was 4.4 kg (IQR, 3.8 to 5.4 kg).
Presenting clinical features included collapsing/syncopal episodes (n = 27) described as seizure-like activity in 3 of these cats, obtundation/abnormal mentation (6), tachypnea/dyspnea (6), lethargy (3), weakness (2), abdominal distension (2), weight loss (2), and ataxia (1). In most cats, a combination of clinical signs was reported, while 7 cats showed no clinical signs strictly associated with the cardiovascular system.
Findings at physical examination included bradycardia (n = 31), increased respiratory effort (5), reduced lung sounds (2), distended abdomen (2), muffled lung sounds (2), jugular vein pulsation (1), pale mucous membranes (1), and right forelimb lameness (1). Collapsing/syncopal episodes (n = 27) and bradycardia (31) were the main reasons for referral.
The ECG diagnosis and indications for ACP were the following: third-degree AVB (29 of 39), high-grade second-degree AVB, paroxysmal third-degree AVB (8 of 39), and sick sinus syndrome (2 of 39). Median ventricular rate of all cats prior to EP implantation was 96 complexes/min (IQR, 80 to 116 complexes/min). At the time of the pacemaker implantation, 14 of 39 cats had a coexisting hypertrophic cardiomyopathy (HCM), ranging from mild left ventricular wall thickening with normal left atrial dimensions to suspected end-stage disease. In 5 cats, the presence of CHF was reported at the time of pacemaker implantation. No other concurrent cardiac diseases were reported.
Twenty-one of 39 cats had a concurrent noncardiac disease (Table 2). A transvenous pacemaker was not attempted in any of the cats.
Concurrent extracardiac conditions in cats undergoing epicardial pacemaker (EP) placement (N = 20 cats).
| Concurrent extracardiac conditions | No. of cats |
|---|---|
| Hyperthyroidism | 6 |
| Diabetes mellitus | 6 |
| Chronic kidney disease | 5 |
| Feline lower airway disease | 5 |
| Urinary tract infection | 3 |
| Cholelithiasis | 1 |
| Megacolon | 1 |
| Acromegaly | 1 |
| Feline injection site sarcoma | 1 |
| Pinna neoplasia | 1 |
| Osteoarthritis | 1 |
| Nodular pneumopathy | 1 |
| Allergic skin disease | 1 |
Surgical procedures
Median time from diagnosis to EP implantation was 2 days (IQR, 1 to 14 days). All surgical procedures were performed by—or under the direct supervision of—a European or American College of Veterinary Surgeons board-certified or Royal College of Veterinary Surgeons specialist surgeon. According to the American Society of Anesthesiologists (ASA) scoring system, 18 of 39 cats were considered ASA 3, 15 of 39 cats were ASA 4, and 1 of 39 cats was ASA 5. In 5 of 39 cats, ASA status was not reported. Median surgical time was 80 minutes (IQR, 62 to 110 minutes), and median anesthetic time was 145 minutes (IQR, 110 to 190 minutes). Under general anesthetic, cats were temporarily paced by use of transthoracic stimulation with defibrillator pads or temporary epicardial leads. Epicardial pacemakers were implanted with the use of an abdominal transdiaphragmatic approach in all cats. A unipolar system was implanted in 13 cats and a bipolar system in 26 cats. The EP leads were fixed to the epicardium with 2 to 3 polypropylene (5-0 to 4-0) sutures. In 35 cats, the generator was placed in a muscular pocket between the internal abdominal oblique and transversus abdominis in the left body wall, whereas in 4 cats, it was placed on the right body wall.
Perioperative intravenous antibiotics were administered in 31 cats and included cefuroxime (10 to 20 mg/kg, q 90 to 120 minutes) and amoxicillin–clavulanic acid (20 mg/kg, q 90 to 120 minutes). Antibiotic use was not recorded in 8 cats.
Six concomitant procedures were performed in 6 cats including liver biopsies (n = 3), right forelimb radiographs and elbow arthrocentesis (1), CT of the brain (1), and MRI of the brain (1). In 22 cats, the pleural space was drained with a transdiaphragmatic catheter or drain prior to abdominal closure. A chest drain was placed in 11 cats, and it was removed between 12 and 31 hours after surgery. The method of thoracic drainage was not recorded in 6 cats. Antibacterial and analgesic therapy was prescribed postoperatively; 9 cats received a course of antibiotics, ranging from 7 to 14 days postoperatively.
Initially, all pacemakers were set to a ventricular demand pacing mode or reprogrammed to a rate-responsive ventricular demand pacing mode, with rates ranging from 90 to 140 beats/min, tailored to each cat’s perceived needs and the cardiologist’s preference.
Complications and outcome
Surgery was uncomplicated in 36 of 39 cats, and all cats survived the surgical procedure. Three cats suffered an intraoperative complication including hypotension (n = 1; mean arterial pressure < 60 mm Hg for 15 minutes), hypothermia (1; < 37.2 °C), and cardiopulmonary arrest followed by 24 hours of self-resolving blindness (1).
In the postoperative period, 14 of 39 cats suffered a total of 19 complications (Table 3), of which 11 of 39 cats suffered 16 pacing-related complications. Seven cats required only adjustment of the EP settings, whereas 4 cats required a surgical intervention including replacement of the EP leads (n = 3) and replacement of the generator (1).
Postoperative complications, time, treatment, and classification in cats undergoing EP placement.
| Case | Signalment | Complication | Treatment | Time | Classification |
|---|---|---|---|---|---|
| 1 | DLH (FN, 13 y, 4.6 kg) | Failure to capture (exit block and return of clinical signs) | Amplitude increased | 432 d | Mild |
| Failure to capture (exit block and return of clinical signs) | Amplitude increased | 712 d | Mild | ||
| 2 | DSH (MN, 8 y, 5.4 kg) | Failure to capture (exit block and return of clinical signs) | Amplitude increased | 439 d | Mild |
| 3 | DSH (MN, 13 y, 4.8 kg) | Failure to capture (faulty generator) | Generator replaced | < 24 h | Severe |
| 4 | Birman (FN, 13 y, 3.8 kg) | Noise reversion at high heart rates | Decreased ventricular refractory period | 1,030 d | Mild |
| 5 | DSH (MN, 15 y, 5.6 kg) | Failure to capture (exit block and return of clinical signs) | Amplitude increased | 259 d | Mild |
| Failure to capture (exit block and return of clinical signs) | Amplitude increased | 506 d | Mild | ||
| 6 | DSH (FN, 12 y, 3.7 kg) | Leads dislodgment | Lead replacement | 10 d | Severe |
| Muscle twitching | Amplitude reduced | 383 d | Mild | ||
| Undersensing | Reduced refractory period | 1,247 d | Mild | ||
| 7 | Bengal (MN, 8 y, 4.1 kg) | Leads dislodgment | Lead replacement | 364 d | Severe |
| 8 | DSH (FN, 8 y, 5.5 kg) | Noise reversion | Decreased ventricular refractory period | 425 d | Mild |
| 9 | DSH (FN, 14 y, 4.2 kg) | Noise reversion | Decreased ventricular refractory period | 365 d | Mild |
| Failure of capture | Amplitude increased | 365 d | |||
| 10 | DSH (FN, 8 y, 5.5 kg) | Suspected pulmonary thromboembolism | Oxygen, furosemide | 4 d | Severe |
| 11 | Persian (MN, 10 y, 3.4 kg) | Lead fracture, right-sided heart failure | Lead replacement | 587 d | Severe |
| 12 | DSH (MN, 15 y, 6.5 kg) | Superficial corneal ulcer | Eye lube | 1 d | Mild |
| 13 | DSH (FN, 10 y, 2.8 kg) | Diaphragmatic twitching (hiccups) | Reduced pacemaker amplitude | 371 d | Mild |
| 14 | Ragdoll (MN, 4 y, 3.9 kg) | CHF and seizures | Furosemide, benazepril, spironolactone, pimobendan, phenobarbital | 9 d | Severe |
CHF = Congestive heart failure. DLH = Domestic longhair. DSH = Domestic shorthair. FN = Female neutered. MN = Male neutered.
All cats survived to discharge. Follow-up was available for all cats and ranged from 9 to 2,285 days (median, 719 days). Seven cats were lost to follow-up between 30 and 1,095 days. Twenty-six cats died or were euthanized during the follow-up period between 9 and 2,285 days, 7 of which were for suspected heart-related conditions (Table 4). Median survival time for all cats was 1,384 days (95% CI, 713 to 2,054 days).
Cause of death and survival time in cats undergoing EP placement.
| Cause of death | Cats (n) | Survival (d) |
|---|---|---|
| Suspected cardiac related | ||
| Hypertrophic cardiomyopathy and aortic thromboembolism | 2 | 486, 2,285 |
| CHF and end-stage hypertrophic cardiomyopathy | 1 | 2,190 |
| Sudden death | 1 | 9 |
| CHF | 1 | 30 |
| Suspected thromboembolism | 1 | 947 |
| Pulmonary thromboembolism, pulmonary hypertension, and chylothorax | 1 | 10 |
| Not cardiac related | ||
| Renal failure | 4 | 365, 572, 719, 850 |
| Uncontrolled diabetes mellitus | 3 | 14, 138, 871 |
| Urinary bladder neoplasia, pancreatitis | 1 | 2,087 |
| Renal failure and diabetes mellitus | 1 | 1,528 |
| Intestinal lymphoma | 1 | 917 |
| Bilateral ureteral obstruction | 1 | 295 |
| Granulomatous bronchopneumonia, seizure | 1 | 29 |
| Neoplasia (unknown) | 1 | 365 |
| Unknown (EP reported to be working well) | 5 | 229, 1,384, 1,400, 1,825, 2,176 |
Health-related quality of life questionnaire
Twenty-one of the 39 owners completed both preoperative and follow-up questionnaires. Results comparing scores for each individual question between the 2 time points are reported in Figure 1.
The impact of epicardial pacemaker (EP) placement in cats on clinical signs, activity levels, and quality of life (median values). Bolded variables are statistically significant (significance set at P < .05), including collapsing (P = .008), wobbliness (P = .0350), lethargy (P = .033), rapid breathing (P = .042), and quality of life (P = .002).
Citation: Journal of the American Veterinary Medical Association 263, 3; 10.2460/javma.24.09.0586
No statistical difference was present in respect of vomiting and inappetence, activity levels, or activities like playing, interaction with other pets, or interaction with the owners. Scores from 4 questions (collapsing/syncope [P = .008], wobbliness/weakness [P = .035], lethargy [P = .033], and rapid breathing [P = .042]) were significantly decreased (indicating improvement) between the 2 time points after EP placement.
In the postoperative period, 1 cat experienced episodes of hiccups on a monthly basis, whereas 3 cats experienced muscle twitching less than once a week (n = 2) and less than once a month (1); however, owner perception of quality of life was not adversely affected.
Owners reported a good improvement in their cats’ general condition following EP implantation, with average score of 9.3 out of 10. Additionally, they expressed an excellent degree of satisfaction with their cat’s response to surgery, averaging 9.9 out of 10, and a low level of worry or concern about their cat’s condition, averaging 1.5 out of 10. There was a significant increase in overall HRQoL scores in cats undergoing EP placement from preoperatively to long-term follow-up (P = .002).
Discussion
The results of this study confirmed that (1) EP placement led to the resolution of clinical signs and so was an excellent treatment option for cats with clinical bradyarrhythmias, and (2) that cats experienced improved HRQoL following EP implantation, with high levels of owner satisfaction and low levels of concerns about their cats’ condition, thus supporting both initial hypotheses.
The signalment, presenting clinical signs, ECG diagnosis, and concurrent heart diseases in the study reported here were consistent with previous reports.3,4,11,12 The majority of cats were diagnosed with either sustained or paroxysmal third-degree AVB or high-grade second-degree AVB.3,4,11,12
Currently, there are no clear guidelines for the use of EP in cats, but the presence and severity of clinical signs related to the cardiovascular system are consistent indications.2,3,12 Cats are believed to tolerate bradyarrhythmias better than dogs and are less susceptible to sudden death due to bradyarrhythmias.2 The resolution of clinical signs is a well-documented outcome for cats after EP placement,3,11,12 and this study confirmed these findings, especially for clinical signs such as collapse and tachypnea/dyspnea. Even for cats that were presented with clinical signs not directly related to the cardiovascular system, resolution of clinical signs and good quality of life were reported, raising the possibility that asymptomatic cats could still benefit from the procedure.
In this study, all EPs were implanted via a transdiaphragmatic approach, though alternative methods, such as intercostal thoracotomy4,6,13 or median sternotomy,3 have also been reported in cats. Further studies are needed to assess any potential benefits associated with different surgical approaches.
In this cohort, 5 cats (13%) experienced at least 1 episode of CHF before surgery. While CHF was documented to have a trend toward decreased survival in dogs,21,23 recent studies3,15 of both dogs and cats undergoing EP placement have shown no adverse outcomes or complications in these patients, indicating that adequate management of CHF prior to surgery can facilitate a favorable outcome. Spalla et al11 reported CHF as the only independent risk factor for cardiac death in cats with persistent third-degree or paroxysmal high-grade AVB, suggesting a potential protective effect of EP in such cases (only 15 of 64 cats underwent APC in that study, 3 of which were in CHF).
Fourteen cats were diagnosed with a coexisting HCM, similar to the findings of Frantz et al3 of cardiac changes in 45% of cats with various forms of cardiomyopathy. Cardiomyopathy is a common feature in cats, reported in 39% of cats with third-degree AVB,2 and in 80% of cats with high-grade second-degree AVB, third-degree AVB, or atrial standstill,12 with no influence on the final outcome for these cats. Rossanese et al15 reported that dogs diagnosed with coexisting cardiac pathology at the time of the EP implantation had a shorter life expectancy compared to dogs without. In the study reported here, prognostic factors were not investigated given the low number of cats that died from a cardiac-related cause; while coexisting cardiomyopathy did not appear to influence the final outcome, the limited sample size prevented drawing definitive conclusions. Future studies focusing on the presence of cardiomyopathy are necessary to determine whether this factor influences outcomes.
Previous studies3,4,12 of EP in cats have documented complication rates up to 75%, with major complications ranging from 40% to 55%. In the current study, the complication rate was 36%, which is substantial but lower than previously reported.3,4,12 Most complications were minor, requiring only minor pacing settings adjustments and having no impact on the outcome.
As previously reported,2–4,12 failure of capture or sensing were the most common complications, occurring from < 24 hours to 1,247 days after surgery, often resulting in a return of clinical signs. Of the 10 cats experiencing such complications, 3 cats required lead replacement and 1 cat required battery replacement; none of these postoperative complications resulted in death. This finding aligned with that of Rossanese et al15 in dogs but contrasted with other studies that indicated an association24 or a trend toward12 a shorter survival time in dogs with major complications. Therefore, active monitoring and regular checks for EP malfunction or complications are crucial, especially if a recurrence of clinical signs occurs.
In this study, 7 cats died of either suspected or confirmed cardiac-related conditions. However, given the retrospective nature of the study, it was difficult to determine whether the reason for death or euthanasia was specifically linked to EP or other cardiac reasons (ie, thromboembolism, sudden death, HCM, and CHF). Colpitts et al4 reported no significant difference in survival between cats with AVB undergoing EP placement versus those not undergoing the procedure, despite a difference in MST (1,278 vs 213 days, respectively). However, cats were not censored on the basis of the reason for death or euthanasia, and the study had a very low number of cats. Frantz et al3 reported an all-cause mortality MST of 948 days, whereas Spalla et al11 highlighted the importance of considering the cause of death or euthanasia, noting a significant difference between cardiac-related death (MST of 133 days) and non–cardiac-related death (MST of 874 days). The same study11 also noted that EP placement did not affect overall survival time, likely because most cats with an EP were still alive at the study’s conclusion.
Future studies are needed to compared survival between cats with AVB undergoing EP placement and those not undergoing EP placement. While our study did not investigate this specifically, we can clearly state that EP implantation led to the resolution of clinical signs and an improved HRQoL.
A recent study15 of dogs undergoing EP placement examined HRQoL as an outcome measure with the use of a questionnaire to assess clinical signs and HRQoL after surgery. The study15 reported a significant decrease in total scores from preoperative to postoperative time points, reflecting the resolution of collapse, breathing difficulties, inappetence, and lethargy, along with increased activity levels and improved HRQoL following EP implantation.
The current study used the same questionnaire to evaluate cats undergoing EP implantation, yielding similar results with excellent HRQoL after EP placement and high levels of owner satisfaction. This underscores the importance of HRQoL for cats, beyond overall survival time. Unlike in dogs, there was no notable difference in activity levels and the level of owner concern was comparatively low. One possible reason for the lack of notable difference in activity levels in cats as compared to dogs could be the inherent differences in behavior and activity patterns between the 2 species. Cats generally have more varied and less predictable activity levels, often interspersed with long periods of rest and independent activity.25 This variability might make it harder to detect significant changes in activity after surgery. Furthermore, the resolution of clinical signs might have a more pronounced impact on the perceived quality of life for cats, overshadowing more subtle changes in activity levels.
Many cats presented with episodes of collapse and tachypnea/dyspnea, which are highly distressing for their owners. The resolution of these clinical signs likely provided significant relief to the owners, as the improvement was substantial compared to their initial concerns. This complete resolution not only contributed to a perceived enhancement in the cats’ quality of life but also reduced the burden of caregiver concern about their cats’ conditions.
The primary limitation of this study was its retrospective design, which relied on the use of clinical records. The potential for incomplete medical records and inconsistent follow-up data could have influenced the accuracy of the findings. Minor complications might have been overlooked, as transient and self-limiting minor cardiac rhythm changes may not have been documented. The outcome measures for the cats in this study were derived entirely from a nonvalidated, owner-based questionnaire, which may have been less reliable due to potential owner bias. The wide range of follow-up periods could have introduced recall bias, with owners who completed the questionnaire long after their cat’s surgery potentially having less precise recall of their cat’s clinical outcome. Additionally, there was a possibility of selection bias, as owners whose cats were clinically improved might have been more likely to complete the questionnaire.
In conclusion, this study provided evidence supporting EP implantation as the method of choice to achieve adequate ACP in cats. The rate of complications was lower compared to previous studies, with most being minor and not significantly affecting the overall outcome. The HRQoL of the cats appeared to be excellent following EP implantation, showing resolution of clinical signs, improvement in quality of life, and high satisfaction among owners.
Supplementary Materials
Supplementary materials are posted online at the journal website: avmajournals.avma.org.
Acknowledgments
The authors would like to thank all the cardiologists and surgeons at the Royal Veterinary College, the University of Liverpool, the University of Bristol, and North Downs Specialist Referrals for their crucial role in diagnosing, managing, and treating the patients in this study. Their expertise and dedication were essential to this research, and the authors are deeply grateful for their support.
Disclosures
The authors have nothing to disclose. No AI-assisted technologies were used in the generation of this manuscript.
Funding
The authors have nothing to disclose.
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