Pulmonary and Paradoxical Embolism after Slow Pathway Ablation: A Thrombotic Disorder Unmasked by a Rare Complication.

Cardiac electrophysiology study (EPS) and catheter ablation procedure are established diagnostic and therapeutic procedures for cardiac arrhythmias. Pulmonary embolism (PE) is a relatively rare but potentially fatal complication of Cardiac electrophysiology study (EPS). The paradoxical embolism (PDE) occurs due to an intracardiac defect with a right to left shunt with patent foramen ovale (PFO) being the most common cause. The simultaneous occurrence of PE and PDE is rare. Here we present a case of PE and PDE after EPS and radiofrequency catheter ablation (RFCA) of the slow pathway in a patient with recurrent supraventricular tachycardia (SVT) due to atrioventricular nodal reentry tachycardia (AVNRT). To our knowledge, such a case of PE and PDE has not been reported after SVT ablation.

Bioprosthetic tricuspid valve dysfunction in patients with transvalvular or epicardial pacing leads.

BACKGROUND: Dysfunction of native tricuspid valves due to transvenous pacing leads is well described. Patients with bioprosthetic tricuspid valve (BTV) who need ventricular pacing are often advised epicardial lead placement to avoid potential damage to the BTV although there are no data to support this. OBJECTIVE: The aim of the study was to assess the frequency of BTV dysfunction in patients with permanent transvenous right ventricular pacemaker lead and compare it to patients with epicardial leads. METHODS: A retrospective review of patients with BTV with ventricular pacing lead was conducted. Demographics, lead, BTV, and echocardiographic data were collected. Frequency of BTV dysfunction (moderate or severe) regurgitation or stenosis was compared between epicardial and transvalvular lead groups. RESULTS: Forty-six patients with BTV and ventricular pacing lead (20 transvalvular and 26 epicardial leads) were identified. Mean age was 46 years with the majority being female (85%) and with rheumatic heart disease (87%). Both groups were similar in age, sex, and indications for BTV. Mean echocardiographic follow-up was for 5.5 years (±4.1 years). BTV dysfunction was similar between the transvalvular group with six (30%) patients and the epicardial group with five (19.2%) patients. The incidence of BTV dysfunction was greater in patients in sinus rhythm compared to patients in atrial fibrillation (50% vs 10%, P  =  0.004). CONCLUSION: Development of BTV dysfunction is similar in patients with transvalvular ventricular leads and epicardial leads. The incidence of BTV dysfunction was higher in patients with sinus rhythm compared to atrial fibrillation.

Appropriate and Inappropriate Implantable Cardioverter Defibrillators Therapies in Arrhythmogenic Right Ventricular Cardiomyopathy/Dysplasia Patients.

BACKGROUND: Arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) is an inherited cardiomyopathy characterized histologically by the replacement of ventricular myocardium with fibrous and fatty tissue, and clinically by ventricular tachycardia arrhythmias primarily of right ventricular (RV) origin. Implantable cardioverter defibrillator (ICD) is the only proven therapy to reduce mortality in ARVC/D patients. However, it has the risk of inappropriate anti-tachycardia pacing (ATP) or shocks. This study aimed to assess the occurrence of appropriate and inappropriate ICD therapies in ARVC/D patients who underwent ICD implantation in a single Cardiac Centre. METHODS: Retrospective analysis of the data of patients with the diagnosis of ARVC/D based on the 2010 revised Task Force Criteria, who underwent ICD implantation in the Heart Centre, at King Faisal Specialist Hospital and Research Center (KFSH&RC), Riyadh between January 1997 and May 2016. The clinical data and information about appropriate and inappropriate ICD therapies were obtained from medical records with the review of the available intra-cardiac electrograms (EGMs). RESULTS: Twenty-two ARVC/D patients with ICD implantation (20 males (91%), mean age at ICD implantation: 32 ± 14 years). ICD was implanted for secondary prevention of sudden cardiac death (SCD) in 15 patients (68.2%), and for primary prevention in 7 patients (31.8%). At mean follow-up of 9.4 ± 4.8 years, 11 patients (50%) had appropriate ICD therapies, and five patients (22.7%) had inappropriate ICD therapies. Out of 950 ICD therapies, 865 (91%) were appropriate (586 episodes of VT/VF treated with ATP (61.3%), and 279 episodes treated with shocks (29.37%)) and 85 (9.4%) were inappropriate (45 episodes treated with ATP (4.73%), and 40 treated with shocks (4.21%)). CONCLUSION: ARVC/D patients are at risk of VT/VF arrhythmias. ICD therapy is the only proven life-saving therapy in those patients. Most of ICD therapies in our patient's population are appropriate, and ATP therapy is effective in terminating most of VT episodes. Although we do not have any patient with subcutaneous ICD, the high success rate of ATP suggests that transvenous ICD would be more appropriate in ARVC/D patients.

Increases in Heart Rate Variability Signal Improved Outcomes in Rapid Response Team Consultations: A Cohort Study.

BACKGROUND: Reduced heart rate variability (HRV) indicates dominance of the sympathetic system and a state of "physiologic stress." We postulated that, in patients with critical illness, increases in HRV might signal successful resuscitation and improved prognosis. METHODS: We carried out a prospective observational study of HRV on all patients referred to the rapid response team (RRT) and correlated with serial vital signs, lactate clearance, ICU admission, and mortality. RESULTS: Ninety-one patients were studied. Significantly higher HRV was observed in patients who achieved physiological stability and did not need ICU admission: ASDNN 19 versus 34.5, p=0.032; rMSSD 13.5 versus 25, p=0.046; mean VLF 9.4 versus 17, p=0.021; mean LF 5.8 versus 12.4, p=0.018; and mean HF 4.7 versus 10.5, p=0.017. ROC curves confirmed the change in very low frequencies at 2 hours as a strong predictor for ICU admission with an AUC of 0.772 (95% CI 0.633, 0.911, p=0.001) and a cutoff value of -0.65 associated with a sensitivity of 78.6% and a specificity of 61%. CONCLUSIONS: Reduced HRV, specifically VLF, appears closely related to greater severity of critical illness, identifies unsuccessful resuscitation, and can be used to identify consultations that need early ICU admission.

Clinical profile and mutation spectrum of long QT syndrome in Saudi Arabia: The impact of consanguinity.

BACKGROUND: Congenital long QT syndrome (LQTS) is an inherited, potentially fatal arrhythmogenic disorder. At least 16 genes have been implicated in LQTS; the yield of genetic analysis of 3 genes (KCNQ1, KCNH2, and SCN5A) is about 70%, with KCNQ1 mutations accounting for ∼50% of positive cases. LQTS is mostly inherited in an autosomal dominant pattern. Systemic analysis of LQTS has not been previously conducted in a population with a high degree of consanguinity. OBJECTIVES: To describe the clinical and molecular profiles of LQTS in the highly consanguineous Saudi population. METHODS: Fifty-six Saudi families with LQTS were consecutively recruited and evaluated. Sequencing of KCNQ1, KCNH2, and SCN5A genes was conducted on all probands, followed by screening of family relatives. RESULTS: Genetic analysis was positive in 32 (57.2%) families, with mutations in KCNQ1 identified in 28 families (50%). Surprisingly, 17 (53.1%) probands were segregating homozygous mutations. Family screening identified 123 individuals with mutations; 89 (72.4%) were heterozygous, 23 (18.7%) were homozygous, and 11 (8.9%) were compound heterozygous. Compared to heterozygous, the phenotype was more severe in homozygous individuals, with cardiac symptoms in 78.3% (vs 12.4%), family history of sudden death in 64.7% (vs 44.4%), and prolonged QT interval in 100% (vs 43.8%). Congenital deafness was found in 11 (47.8%) homozygous probands. CONCLUSION: Our study provides insight into the clinical and molecular profiles of LQTS in a consanguineous population. It underscores the importance of preemptive management in homozygous patients with LQTS and the value of clinical and molecular screening of at-risk relatives.

Subcutaneous Implantable Cardioverter Defibrillators Implantation Without Defibrillation Threshold Testing: A Single Center Experience.

BACKGROUND: Subcutaneous implantable cardioverter defibrillator (S-ICD) system has been proven to be an effective therapy for prevention of sudden cardiac death (SCD) in selected patients. Although the Shockless IMPLant Evaluation (SIMPLE) trial has shown that defibrillation threshold (DFT) testing is not necessary for transvenous ICD (TV-ICD) systems, it is still recommended for S-ICD systems. We aimed to study the efficacy and safety of S-ICD implantation without DFT in our Heart Center with the comparison of S-ICD patients' outcome to those with a single chamber TV-ICD without DFT in the same period. METHODS: A retrospective analysis of patients underwent S-ICD without DFT from December 2014 to May 2016 with the comparison to single chamber TV-ICD patients implanted during the same period. RESULTS: Thirty consecutive patients (23 males (76.7%); mean age 41 ± 13 years; mean left ventricular ejection fraction 30±12%) received a S-ICD for primary (25 patients, 83.3%) or secondary prevention (five patients, 16.7%) of SCD. During a mean follow-up of 710.6 ± 190 days, three patients received 38 appropriate ICD shocks (90.5%), and two patients received four inappropriate shocks (9.5%). There were two mortalities (6.7%): one cardiac and one non-cardiac. When compared to 30 consecutive who received a single chamber TV-ICD during the same period, there was no significant difference in mortality. CONCLUSIONS: Implantation of S-ICD using intermuscular approach without DFT seems to be safe and effective. Data from large S-ICD registries with long-term follow-up, and preferably randomized controlled studies, are needed to confirm this finding.

Predictors of Permanent Pacemaker Implantation After Coronary Artery Bypass Grafting and Valve Surgery in Adult Patients in Current Surgical Era.

BACKGROUND: Permanent pacemaker (PPM) implantation after cardiac surgery is required in 0.4-6% of patients depending on cardiac surgery type. PPM implantation in the early postoperative period may reduce morbidity and postoperative hospital stay. We performed a retrospective review of electronic medical records of adult patients with coronary artery bypass grafting (CABG), valve surgery, or both, over a 3-year period. Our aim was to identify predictors of PPM requirements and PPM dependency on follow-up in the current surgical era. METHODS: After exclusion of patients with congenital heart disease, patients who already had a PPM or implantable cardioverter defibrillator (ICD), and patients with an indication for PPM or ICD before surgery, we identified 1,234 adult patients who underwent cardiac surgery between January 2007 and December 2009. A retrospective review of electronic medical records and pacemaker clinic data was performed. RESULTS: Patients' mean age was 46.65 ± 16 years, and 59% were males. CABG was performed in 575 (46.6%) cases, aortic valve replacement in 263 (21.3%), mitral valve replacement in 333 (27%), and tricuspid valve replacement in 76 patients (6.2%). Twenty patients (1.6%) required implantation of a PPM postoperatively. Indications for PPM implantation included complete atrioventricular (AV) block in 13 (65%), sick sinus syndrome in three (15%), and atrial fibrillation (AF) with a slow ventricular rate in four (20%). Predictors for PPM requirement by multivariate analysis were the presence of pulmonary hypertension (P-HTN), reoperation, and left bundle branch block (LBBB) (P < 0.05). Late follow-up was available in 18 patients, at 84.5 ± 30 months. Eleven patients (61%) were PPM dependent on long-term follow-up. CONCLUSIONS: Patients at high risk for PPM implantation after cardiac surgery include those with P-HTN, reoperation, and pre-existing LBBB. Of those receiving a PPM, about one-third will recover at least partially at long-term follow-up. We recommend preoperative assessment for risk of requiring postoperative PPM, to counsel patients about this risk and early PPM implantation in high-risk patients who are PPM dependent after surgery.

The Gulf Implantable Cardioverter-defibrillator Registry: Rationale, Methodology, and Implementation.

BACKGROUND: The implantable cardioverter-defibrillator (ICD) is effective in the prevention of sudden cardiac death in high-risk patients. Little is known about ICD use in the Arabian Gulf. We designed a study to describe the characteristics and outcomes of patients receiving ICDs in the Arab Gulf region. METHODS: Gulf ICD is a prospective, multi-center, multinational, and observational study. All adult patients 18 years or older, receiving a de novo ICD implant and willing to sign a consent form will be eligible. Data on baseline characteristics, ICD indication, procedure and programing, in-hospital, and 1-year outcomes will be collected. Target enrollment is 1500 patients, which will provide adequate precision across a wide range of expected event rates. RESULTS: Fifteen centers in six countries are enrolling patients (Saudi Arabia, United Arab Emirates, Kuwait, Oman, Bahrain, and Qatar). Two-thirds of the centers have dedicated electrophysiology laboratories, and in almost all centers ICDs are implanted exclusively by electrophysiologists. Nearly three-quarters of the centers reported annual ICD implant volumes of ≤150 devices, and pulse generator replacements constitute <30% of implants in the majority of centers. Enrollment started in December 2013, and accrual rate increased as more centers entered the study reaching an average of 98 patients per month. CONCLUSIONS: Gulf ICD is the first prospective, observational, multi-center, and multinational study of the characteristics and, the outcomes of patients receiving ICDs in the Arab Gulf region. The study will provide valuable insights into the utilization of and outcomes related to ICD therapy in the Gulf region.

Arrhythmogenic right ventricular cardiomyopathy/dysplasia in Saudi Arabia: a single-center experience with long-term follow-up.

BACKGROUND AND OBJECTIVES: Arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) is a rare genetic disorder that primarily involves the right ventricle (RV). It is characterized by progressive replacement of RV myocardium by fibrofatty tissues. It commonly presents with ventricular tachycardia (VT) of RV origin and may result in RV failure. The aim of this study is to evaluate the clinical characteristics of adult patients with ARVC/D treated at the Heart Centre, King Faisal Specialist Hospital and Research Centre (KFSH&RC), Riyadh, Saudi Arabia. DESIGN AND SETTINGS: This is a retrospective study of patients with ARVC/D diagnosed and treated at the KFSH&RC Heart Centre in Riyadh. PATIENTS AND METHODS: Twenty-two cases with ARVC/D with regular follow-up at our Heart Centre from January 2007 to May 2010 were included in this study. The diagnosis of ARVC/D was made according to the revised International Task Force Criteria. The clinical data were collected from patients' charts and electronic medical records. RESULTS: The majority of patients were males (18; 82%). The diagnosis of ARVC/D was definite in 18 patients (82%), borderline in 2 (9%), and possible in 2 (9%). The mean age at diagnosis was 33.3 years. The follow-up period ranged from 29 to 132 months, with a mean follow-up period of 84 months. Ten patients presented with sustained VT, and 3 were survivors of cardiac arrest. Electrocardiogram abnormalities were present in 16/22 patients (72.7%). Echocardiographic changes meeting major diagnostic criteria were seen in 16 patients (76%). Cardiac magnetic resonance imaging was performed in 11 patients, and showed changes compatible with major diagnostic criteria in 7 patients (64%). Implantable cardioverter defibrillators (ICDs) were implanted in 17 patients; 8 had appropriate ICD shocks and 5 had inappropriate ICD shocks. Antitachycardia pacing was effective in terminating most of the VT/ventricular fibrillation episodes. CONCLUSION: ARVC/D is a rare but increasingly recognized heart muscle disease seen in Saudi Arabia and other parts of the world. It is associated with a highly nonspecific presentation. VT of RV origin is a common presentation for this disease. Antiarrhythmic medications and ICD implantation are the main management options.

Cardiac electrophysiology studies and ablations for treatment of supraventricular arrhythmias--an initial experience from Karachi.

OBJECTIVES: To review the clinical experience, complications and outcome of Cardiac Electrophysiology Studies and Catheter Radiofrequency Ablation in treatment of supraventricular tachycardias in Karachi. METHODS: A retrospective review of records of all patients who underwent an electrophysiological study and radiofrequency ablation at National Institute of Cardiovascular Diseases and Aga Khan University Hospital from 2005 to 2007 was performed. Patient's demographics, disease and procedural data were collected and analyzed using SPSS.V.II. RESULTS: We enrolled 168 patients, 150 (89%) from National Institute of Cardiovascular Diseases and 18 (11%) from Aga Khan University Hospital. Sample had 86 (51%) male participants. The mean age was 43 +/- 15 years. Indications for procedure were recurrent supraventricular tachycardias (89.9%), Wolff Parkinson White Syndrome with atrial fibrillation (5.9%), syncope (2.4%), and wide QRS tachycardia (1.8%). Final diagnosis was Wolff Parkinson White Syndrome in 80 (48%) and Atriovetricular Nodal Reentrant Tachycardia in 88 (52%). The accessory pathway in Wolff Parkinson White Syndrome was located on left side in 61% of cases and on right side in 39% of cases. Overall acute success rate for Radio Frequency ablation was 90%. Success rate for ablation of accessory pathway in Wolff Parkinson White Syndrome was 85% while that for ablation of slow pathway in AV node re-entrant tachycardia was 95%. Complications occurred in one case. CONCLUSION: Electro Physiology Studies and Radiofrequency ablation proved to be a safe and effective method for diagnosis and treatment of supraventricular tachycardias in our patients.

Basic life support skills: assessment and education of spouse and first degree relatives of patients with coronary disease.

OBJECTIVE: To assess the knowledge of basic cardiac life support (BCLS) before and after the institution of training among first degree relatives and spouses of patients with coronary disease. STUDY DESIGN: Quasi-experimental study. PLACE AND DURATION OF STUDY: National Institute of Cardiovascular Diseases, Karachi, from April 2007 to May 2008. METHODOLOGY: A total of 300 relatives of patients with coronary heart disease undertook a one day CPR course. Questionnaire assessing knowledge of CPR was administered before and after the course. Patients were studied in groups of 10-20 at a time. Proportion of correct knowledge was compared using chi-square test with significance at p < 0.05. RESULTS: Mean age of participants was 31.08+10.53 years. Two hundred and twenty (73.34%) were males. On the average for all 31 questions, 37.09% of participants had correct responses before the training and 68.16% after the training of BCLS (p < 0.001). There was statistically significant improvement across all age groups, gender and educational levels (p < 0.01). CONCLUSION: There was significant improvement in relatives' knowledge of BCLS after training. Different age groups, both genders and all educational groups showed equal learning abilities.

Pacemaker patients' perception of unsafe activities: a survey.

BACKGROUND: Cardiac pacing is a recognized and widely used treatment for patients presenting with bradycardia. Physicians expect patients to return to normal activities almost immediately post implantation. However, patients themselves may perceive interference to pacemaker function by various routine activities and devices, and hence continue to lead restricted, disabled lives. The aim of this study is to determine if routine activities are perceived by pacemaker patients to interfere with their device function. METHODS: A descriptive cross sectional survey was carried out on consecutive patients at the pacemaker clinic at a public hospital in Karachi, Pakistan. A 47-question tool was developed and tested. Patients' perceptions of safety of performing various routine activities, along with socio-demographic data were recorded. RESULTS: The final sample included 93 adult patients (45% males). 41% were illiterate. 77.4% recalled receiving counselling at implantation, predominantly from the implanting physician and house staff. A considerable proportion of patients considered many routine activities unsafe including driving automobiles (28%), passing through metal detectors (31%), bending over (37%), and sleeping on the side of the pacemaker (30%). Also considered unsafe were operation of household appliances--TV/VCR (television/video cassette recorders) (53%), irons (55%)) and electrical wall switches (56%). For nearly all variables neither literacy nor history of counselling improved incorrect perceptions. CONCLUSION: This study shows that our pacemaker patients perceive many routine activities as unsafe, potentially leading to disabling life style modifications. The tremendous investment in pacemaker technology to improve patient performance is not going to pay dividends if patients continue to remain disabled due to incorrect perceptions. Further studies are required to determine the reasons for these misperceptions, and to determine if these problems also exist in, and hinder, other patient populations.

Pacemaker-mediated tachycardia induced by left ventriculography during diagnostic catheterisation: a rare event.

Pacemaker-mediated tachycardia (PMT) is an arrhythmia seen in patients implanted with dual-chamber pacemakers. It occurs when ventricular contraction is followed by retrograde conduction to the atrium, which is sensed by the pacemaker, leading to ventricular triggering. A vicious re-entry cycle is set up, leading to incessant tachycardia unless appropriately terminated. A common precipitant is a premature ventricular contraction (PVC). Although PVCs are frequently generated during ventriculography, PMT is an extremely rare event during cardiac catheterisation despite the fact that a large number of patients with implanted pacemakers do undergo the procedure. We report on a case and hope to highlight the possibility of PMT occurring during catheterisation, as well on therapeutic options.

Effect of single dose magnesium on arrhythmias in patients undergoing coronary artery bypass surgery.

OBJECTIVE: To evaluate the safety and role of prophylactic administration of magnesium in preventing arrhythmias. METHOD: This double blind randomized placebo controlled clinical trial was conducted at Aga Khan University Hospital on coronary artery bypass surgery patients. All patients were connected to holter monitor before induction of anaesthesia and this monitoring continued for 24 hours. Study drug containing either 2-grams of magnesium or normal saline was given after intubation. Levels of serum magnesium was checked preoperatively and then in ICU at 0, 6, 12, and 24 hours. Independent t-test and chi square test were used for analysis. Statistical significance was defined as p-value < 0.05. RESULTS: A total of 104 patients consented to participate in the study, 53 patients were randomly allocated in magnesium (Mg) group and 51 in placebo group. Two (3.77%) patients in magnesium group and five patients (9.8%) in placebo group developed atrial fibrillation. Incidence of ventricular and supraventricular tachycardia was also slightly higher in placebo. Mg level after arrival in CICU (Cardiac Intensive Care Unit) showed mean of 2.1 in magnesium group and 1.6 in placebo group (p = 0.6). CONCLUSION: Low magnesium levels were noticed in the placebo group after cardiopulmonary bypass and although prophylactic administration of magnesium sulphate was relatively safe but significant benefit on prevention of arrhythmias could not be attained.

Clinical and echocardiographic characteristics of patients with significant pericardial effusion requiring pericardiocentesis.

OBJECTIVE: Clinical and echocardiographic features of significant pericardial effusion (PE) have been reported from the west. Currently there is lack of published data from this part of the world, we reviewed all consecutive cases of significant PE requiring echocardiographic assisted pericardiocentesis to analyze the clinical and echocardiographic features of these patients. METHODS: Forty four consecutive patients who underwent echocardiography assisted pericardiocentesis at the Aga Khan University Hospital (AKUH) between January 1988 and May 2001" re included in this review. RESULTS: Most common presenting symptoms were dyspnea (89%) and fever (36%). Elevated JVP and pulsus paradoxus were documented in 59% and 41% of patients respectively. Sinus tachycardia (75%) and low voltage (34%) were the most common ECG findings. Malignancy (45-51%) and tuberculosis (27%) were among the most frequent causes of PE. One patient died during echocardiography-assisted pericardiocentesis. CONCLUSION: The symptoms and physical findings of haemodynamically significant PE are frequently nonspecific. Transthoracic echocardiography is the gold standard for rapid and confirmatory diagnosis of PE and cardiac tamponade. The most common cause of PE was malignancy followed by tuberculosis. Pericardiocentesis under echocardiographic guidance is a safe and effective treatment for significant PE.

Predicting postoperative cardio-pulmonary complications by a test of stair climbing.

OBJECTIVE: To assess whether a test of stair climbing ability could be used to predict the risk of developing postoperative cardiopulmonary complications in patients undergoing general anesthesia. DESIGN: Cohort study. PLACE AND DURATION OF STUDY: The Aga Khan University Hospital, Karachi. The duration of the study was from December 2003 to December 2004. PATIENTS AND METHODS: This study was carried out on consecutive, adult patients presenting for elective thoracic or abdominal surgery under general anesthesia. Pre-operatively, patients were asked to climb a standard staircase. Number of steps climbed was recorded. Those unable to climb stairs due to debilitating cardiac, pulmonary or rheumatologic disease were categorized as 0 stairs climbed. Outcome variables were postoperative cardiopulmonary complications or mortality. Period of follow-up was until hospital discharge. RESULTS: Seventy-eight patients were enrolled, 59 (75.6%) climbed 1 flight of stairs, 19 (24.3%) climbed < 1 flight. All-cause cardiopulmonary complications rate was 26 %. The most frequent complication was lobar atelectasis, followed by bronchospasm and acute MI. The complication rate was 22.8% in those able to climb 1 flight and 40% in those patients who climbed < 1 flight. The group that climbed < 1 flight tended to have complications associated with poor reserves of the cardiopulmonary systems, i.e. pulmonary edema, exacerbation of underlying lung disease. The relative risk of developing complications, if unable to climb at least 1 flight of stairs, was calculated to be 1.8 (95% CI 0.7 - 4.6). CONCLUSION: Stair climbing can be a useful pre-operative tool to predict the risk of postoperative cardiopulmonary complications.

Survival of patients treated with intra-aortic balloon counterpulsation at a tertiary care center in Pakistan - patient characteristics and predictors of in-hospital mortality.

BACKGROUND: Intra-aortic balloon counterpulsation (IABC) has an established role in the treatment of patients presenting with critical cardiac illnesses, including cardiogenic shock, refractory ischemia and for prophylaxis and treatment of complications of percutaneous coronary interventions (PCI). Patients requiring IABC represent a high-risk subset with an expected high mortality. There are virtually no data on usage patterns as well as outcomes of patients in the Indo-Pakistan subcontinent who require IABC. This is the first report on a sizeable experience with IABC from Pakistan. METHODS: Hospital charts of 95 patients (mean age 58.8 (+/- 10.4) years; 78.9% male) undergoing IABC between 2000-2002 were reviewed. Logistic regression was used to determine univariate and multivariate predictors of in-hospital mortality. RESULTS: The most frequent indications for IABC were cardiogenic shock (48.4%) and refractory ischemia (24.2%). Revascularization (surgical or PCI) was performed in 74 patients (77.9%). The overall in-hospital mortality rate was 34.7%. Univariate predictors of in-hospital mortality included (odds ratio [95% CI]) age (OR 1.06 [1.01-1.11] for every year increase in age); diabetes (OR 3.68 [1.51-8.92]) and cardiogenic shock at presentation (OR 4.85 [1.92-12.2]). Furthermore, prior CABG (OR 0.12 [0.04-0.34]), and in-hospital revascularization (OR 0.05 [0.01-0.189]) was protective against mortality. In the multivariate analysis, independent predictors of in-hospital mortality were age (OR 1.13 [1.05-1.22] for every year increase in age); diabetes (OR 6.35 [1.61-24.97]) and cardiogenic shock at presentation (OR 10.0 [2.33-42.95]). Again, revascularization during hospitalization (OR 0.02 [0.003-0.12]) conferred a protective effect. The overall complication rate was low (8.5%). CONCLUSIONS: Patients requiring IABC represent a high-risk group with substantial in-hospital mortality. Despite this high mortality, over two-thirds of patients do leave the hospital alive, suggesting that IABC is a feasible therapeutic device, even in a developing country.

Outcome of cardiogenic shock complicating acute myocardial infarction.

OBJECTIVE: To analyze the characteristics and in-hospital outcome of patients with cardiogenic shock (CS) complicating acute myocardial infarction (AMI) and to evaluate the influence of urgent coronary revascularization on in-hospital mortality. DESIGN: Descriptive study. PLACE AND DURATION OF STUDY: The Aga Khan University Hospital, Karachi. January 2001 to December 2001. MATERIALS AND METHODS: All consecutive patients with AMI and CS, admitted at The Aga Khan University Hospital, Karachi Pakistan, during the year 2001 were reviewed. A pre-designed questionnaire was used for data collection. Analysis was done using the SPSS statistical package. RESULTS: Out of 615 patients with AMI, 53 (8.6%) had CS. Mean age was 60.9 +10.7 years. 62.3% were men, 52.8% were hypertensive and 43.4% were diabetic. Most infarcts were anterior in location (56.6%). Thrombolytic therapy (Streptokinase) was administered to 43.5% of patients with ST segment elevation myocardial infarction. 64.2% required ventilatory support while swan ganz was used in 37.7%. Intra-aortic balloon pump was inserted in 39.6%. Ventricular tachycardia was the most common complication (39.6%). Overall in-hospital mortality was 54.7%. CS associated with mechanical complications had 80% in-hospital mortality. In patients without mechanical complications (n=48), in-hospital mortality was significantly lower in the revascularization group (31.6% vs. 65.5%, p-value = 0.021). However, there were significant differences in the baseline characteristics in the two groups because of the selection bias. CONCLUSION: CS occurring in patients with AMI has an extremely poor prognosis. Patients selected for revascularization strategy has favorable in-hospital outcome.